London's first big Olympic weekend
This weekend, London will experience a miniature Olympics.
While the Modern Pentathlon World Championships are in full swing at Crystal Palace in south east London, top triathletes will be competing in the latest leg of triathlon's World Championship Series, nine miles north in Hyde Park.
We've been spending some time with top British stars in each of the three sports ahead of this weekend, which is being billed as one of the first proper tests of London's Olympic preparations to date.
Left-right: Triathlete Will Clarke, pentathletes Heather Fell and Katy Livingston, and GB basketball's Luol Deng
Certainly, the appetite is there. All the five-event tickets for the pentathlon (which involves fencing, swimming, show jumping, running and shooting) were sold in advance of Thursday's opening qualifier.
And when the organisers offered reporters a chance to try the new combined run-and-shoot event, I've never seen so many nervous journalists clutching battered pairs of trainers.
Sports editors across the country had clearly decided not to risk it, instead sending along fresh-faced, expendable reporters in case of a gun-related mishap.
That is why I was the one going up against world number one and Plymouth export Heather Fell earlier this week.
In the past, modern pentathletes would do the shooting and the 3km run as separate events. For the very first time in a major competition, they'll now do them at (almost) the same time.
Some of the world's best pentathletes - including Fell and Olympic champion Lena Schoneborn - have struggled with the new event because they aren't rewarded for shooting accuracy in the same way, or can't just concentrate on the run at the end.
That means this weekend will be the first big test of the new event, and how well pentathletes have adapted. I've written a bit more about the run-and-shoot if you're keen.
When London 2012 rolls around, the pentathlon will be spread between various venues, so don't get too attached to the Crystal Palace setting if you go.
Triathlon, on the other hand, gets an early sample of the real deal, because Hyde Park is nailed down as the Olympic venue.
On Saturday, the world's top women (from 1000 BST) and men (1315) will run, swim and bike it around London's most prestigious piece of greenery, knowing that three years hence, they'll do it on the same turf for Olympic gold.
Britain's Will Clarke, who won the London Triathlon last month, blogged earlier this week about the prospect of competing in Hyde Park. He's got a handy map of the route in his blog too.
Leeds man Alistair Brownlee - hot favourite to win the overall title in the world series, which takes in eight cities, London being the sixth - will be up against Clarke, German series leader Maik Petzold and Spain's Javier Gomez.
From Friday to Sunday in the afternoon and evening, the O2 takes up the baton with a series of basketball games in the Four Nations tournament.
If you get a ticket, you could end up sat next to Luol Deng. The 6ft 9in Chicago Bulls star is injured so can't join his British team-mates on court, but will be there watching.
It's been a long and winding road getting even a semi-competitive British team together ahead of the Games, and this weekend is one of the most high-profile chances that team will get to prove its mettle to the British public ahead of time.
Watch out for Joel Freeland. The 22-year-old from Farnham, Surrey, who has already been drafted by an NBA team, is currently plying his trade with top European side Malaga.
Now he has a chance to shine for GB with Deng and star centre Robert Archibald missing.
Freeland and the team played in a European Championship qualifying game at the O2 last year and he told us: "I really enjoyed it. It was different, because basketball is still not so big over here, but it was one of the best arenas I've ever played in so it was really exciting."
Looking ahead to playing in the same place in three years' time, he said: "Anyone would take great pride at playing in the Olympics in any country but in your own country you get that extra pride."
Few Olympic sports in this country can command the facilities of the O2 and, as with pentathlon and triathlon, organisers will be watching carefully to see how their sports fare in a weekend crammed with sporting activity.
Not only have the trio got each other with which to contend, but it's also the start of the Premier League football season. It makes you wonder whether none of these sports fancied shifting the dates a little, and whether a miniature Olympics is a positive or negative thing in such close quarters - without the buzz and audience a full-on Olympics will generate.
"It's a busy calendar and every sport runs into each other, particularly as the performance of British athletes across a range of sports increases," Dominic Mahony, team leader for the British pentathletes, told me.
"It's good to have three Olympic sports being showcased in London. I don't think people will stay away from pentathlon to go to triathlon or vice versa, and I'm hoping the local crowd will come here."
Visit London and the Mayor's office are doing what they can to make sure potential spectators cross-pollinate these budding events in the way Mahony envisages.
They've already dubbed this "London Warm-Up Weekend" and are offering tickets to all three events for £20. But be quick if you're interested, because that price includes basketball on Friday night.
Of course, there are likely to be hitches. For a start, getting to the O2 is made slightly trickier with the Underground's Jubilee Line closed for engineering works (here's some information on other wyas of getting there).
If you can't make it, BBC Sport will have highlights of the Modern Pentathlon World Championships on the red button from 1900 BST each night, and on the web too.
Then I'm back at the pentathlon all day Sunday for the women's final, where I reckon there's a realistic chance of a Briton becoming the new world champion, while my colleague and basketball expert Rob Dugdale will be at the O2 following the GB team's fortunes. Don't miss his excellent preview of their campaign ahead.
If you're going to be at any of the venues it'd be good to hear from you, either via Twitter or in person if you spot me - and I hope you enjoy it!