Warm-up weekend's winners and losers
Who would be an event organiser for an Olympic sport?
The sleepless nights even in 2009, three years from the Games themselves, must be torture.
While the British public aren't yet tattooing the Olympic rings to their chests, organisers know that their sports, other sports, the media, UK Sport, the government, the IOC and others are watching every big sporting event in London from now on.
So how did those events match up, and which Olympic organisers will sleep easiest once their walkie-talkies and lanyards are packed away?
I spent the day travelling between all three events, and there's a clear winner. It's GB Basketball.
A few years ago, the thought of nominating British basketball for anything approaching the title "best organised" would have been ridiculous.
The team itself was only formed in late 2005, so it hasn't even had four years to bed down, yet has the task of proving that Britain deserves to have a home team in the 2012 competition.
Quite how the British team goes about proving it will be competitive in 2012 has never been clearly defined - but this tournament goes some way to showing the sport has got its act together.
For a start, as a minority sport (in terms of British crowd figures at least - basketball is a huge participation sport, but those who play rarely spectate), you need to have real guts to pick a venue like the former Millennium Dome.
I've no idea how much it is costing organisers to host the six-game tournament, but you have to be confident of getting a return, one you can measure in terms of spectators and buzz around your sport.
The arena was by no means full for GB's 70-63 defeat by Turkey on Saturday night, but there were several thousand fans, and they didn't shut up for the entire game.
They were helped, admittedly, by a passionate and vocal Turkish contingent, whose light-hearted barracking of British fans inspired their rivals to answer back.
But as one wide-eyed basketball journalist exclaimed, gazing around the arena: "A British crowd are actually getting into basketball."
Outside the arena, children danced around the concourse with miniature basketballs or tried their hand at a number of basketball-themed games set up by the entrance.
Inside it, fans bathed in a light and sound extravaganza, helped by an under-strength British team finding it within themselves to take Turkey all the way in a genuinely exciting game to watch.
The score had been tied at 48-48 heading into the final quarter. Only in the final five minutes did the British throw it away, stupidly - or rather, tiredly - conceding a succession of free throws which let Turkey out of sight.
But by then, the crowd had taken the bait. Every basket got a cheer. Opposition players were booed (as good-naturedly as it's possible to boo someone) on cue. At one point there was even the threat, enthusiastically received, of a fight on court.
I defy anyone to come away from the O2, slop down on the sofa and say, "Well, that was a bit rubbish."
It pains me to say I'm not sure the same applies to modern pentathlon.
I really like modern pentathlon. To most people it sounds bizarre, and it is a bit odd - it's not a sport you can pick up in a playground, requiring as it does a horse, a sword and a gun - but if you give it a little time to prove itself, it can be a rewarding watch.
Sadly, sports get less and less time to prove themselves.
Basketball gave us 24-second shot clocks, lightning-fast 10-minute quarters, and pounding music dropped into every break in play.
Pentathlon gave us 40 horses being introduced, one by one, to a crowd of a few hundred, and then a further 30-minute wait after the last horse had taken its bow until anyone returned on one to actually compete in the show jumping.
That wait was agonising. I didn't see anybody leave but, given the fencing started nearly six hours earlier and there had been swimming in between, by this point in the day you either had the stamina for the finish or you'd already gone home.
This is a sport that, until fairly recently, allowed five days for each Olympic final to run its course. Cutting it down to one day has been an achievement; trimming it to a length that suits a modern audience will be another matter.
The "combined event", running and shooting at the same time, is being used for the first time at a major competition here. That came into being with the aim of making pentathlon more spectator-friendly.
But it would take the equivalent of cricket's Twenty20 to give pentathlon the edge it's trying to find. How do you distil five events into a few hours? Can you? If you could, would you want to (some might say) rip the heart out of the sport in order to grant it wider appeal?
Sunday at the National Sports Centre in Crystal Palace may be different. That's the women's final, in which there are four British entrants, lending the host nation a strong chance of at least a medal, if not a world champion.
That ought to draw in a bigger crowd and generate a bit more atmosphere, but I suspect the location of the competition really hasn't helped either.
Crystal Palace is a trek out of central London, is well off the tourist trail, and didn't seem to be offering much apart from the pentathlon to the casual visitor. Nor is it the 2012 venue (in three years' time, the climax to the event will come at the temporary venue in Greenwich Park).
Triathlon, by contrast, struck gold by holding its World Championship Series event for the next three years on the Olympic course in the middle of London's Hyde Park.
Hyde Park is central, it's a tourist destination in its own right, and is an open space as popular with locals out for a stroll as it is with people coming to visit.
You could have done no publicity whatsoever for the triathlon - I didn't see much - and still guaranteed an audience in the thousands, based purely on people stumbling across it.
And the crowd watching the elite men's and women's races on Saturday was duly impressive. At the start of the men's race, it was a struggle to fight your way through some of the nearby paths. The transition area (where swimmers ditch their goggles, strap on a helmet, and pedal off on a bike) was briefly lined by crowds four-deep.
Spectators fell into two camps: triathlon enthusiasts, often dressed as though they might reasonably be called to compete as late replacements, and passers-by who had stopped to admire the bewildering event unfolding before them.
When I spoke to members of the latter, they were all earnestly enthusiastic. "Isn't it exciting," cooed a lady propped up on a barrier as the male cyclists thundered past. A young couple had abandoned their Hyde Park roller-blading plans (a wise move) to take in the triathlon instead.
Having Hyde Park as a venue almost guarantees reactions like those, not least because it's impossible to charge anyone to watch, so everybody feels delighted to have snagged free sporting entertainment.
I reckon if you'd pitched up with some horses, fencing mats and a temporary shooting range, you could have held a very successful modern pentathlon there, too.
Triathlon is on to a sure-fire winner with this, and it knows it. In three years' time, that park will be rammed.
But basketball still takes the gold. They got thousands of people out to Greenwich (despite the only tube line to the O2 - the Jubilee - being closed) rigged up an array of games and sideshows for children, and put on a show.
Now, you decide if putting on a show is worth risking what your sport is about. If you were organising modern pentathlon, would you tinker with your sport to make it as watchable and entertaining as possible, or decide that the sport exists as it does for a reason, and leave it be?
I ask because I wonder if pentathlon's Olympic days are numbered - and what will happen to it if afterwards, if that's the case.
Sports like rugby sevens and women's boxing deliver punch, if you'll excuse the pun, in a way pentathlon never will. The sport has to be looking over its shoulder after the IOC looked favourably on those newcomers, and wondering if the axe will fall.
After all, driving home from Greenwich on Saturday evening, which was the only sport (besides football) to make it onto a leading commercial radio station's news bulletin?
The world championships of free running, in Trafalgar Square.
Not one of the Olympic trio warranted a mention. If it's a quest for relevance, there is work to be done. If it's a quest to preserve sports in their purest form, lack of appeal will be the price.
If you were at any of these events - including the free running! - I'd love to know what you made of them, what could have been improved, and what you enjoyed.