Some 500,000 remaining tickets for events at the London 2012 Olympic Games have gone on general sale for a 24-hour period from 11:00 BST (10:00 GMT) on Wednesday, 23 May.
When and how can I buy the tickets?
The sales window opened at 11:00 BST on 23 May.
Ticket sales will be processed via the London 2012 tickets website. Card payments can only be made using Visa cards.
Up to four tickets can be purchased per session, and up to four sessions in one transaction, for all available sports apart from football - where more tickets are available to encourage people to attend in groups.
What sports are available?
There are some £20 tickets left for sports such as volleyball, table tennis, weightlifting, taekwondo, boxing, football and fencing.
Organisers Locog say there is a good number of tickets priced between £45 and £450 in sports including archery, badminton, basketball, beach volleyball, canoe sprint, diving, handball and hockey.
Only a limited number of tickets are available in race walk, mountain biking, sailing, artistic gymnastics, water polo and rowing.
Some sports have sold out and tickets are no longer available for athletics (marathon), canoe slalom, cycling (BMX, road and track), all equestrian (dressage, eventing and jumping), rhythmic gymnastics, modern pentathlon, swimming, marathon swimming and synchronised swimming, tennis, triathlon and opening and closing ceremonies.
Are there any other tickets available?
Yes, ground admission tickets for the Olympic Park are still available. Tickets costing £10 for adults and £5 for young people and seniors will enable spectators to watch action on the big screens but not to enter the venues.
On 29 May tickets will go on sale for:
• Cycling Road Race at Box Hill, Surrey. Tickets will be £15 full price and £5 for young people and seniors for the viewing area at Donkey Green and £10 and £5 for the viewing area at Dormouse Drive.
• Cycling Individual Time Trial at Hampton Court Palace. These tickets will be £15 full price and £5 for young people and seniors at Viewing Area A and £10 and £5 at Viewing Area B.
• Tennis, staged at the All England Club in Wimbledon, providing access to The Hill and the big screen only. These tickets will be £10 full price and £5 for young people and seniors
• The Orbit. Tickets will cost £15 full price and £7 for people aged 16 or under and seniors aged 60 or over. These tickets should only be purchased by people who have an Olympic Park ticket or a sport ticket for an event in the Olympic Park for the day they wish to visit the Orbit.
Can I sell my tickets on the open market?
Section 31 of the London Olympic Games and Paralympic Games Act, passed in 2006, makes it a criminal offence to sell tickets without authorisation from the London Organising Committee (Locog).
Under English law, tickets for Olympic and Paralympic events can only be sold through licensed outlets and the maximum fine for selling tickets on the black market is £20,000.
However, once physical tickets become available holders can sell them for face value to friends and family.
It does not matter if their name does not match the booker's name, which will be on the ticket.
Locog does say, however, that they would need to be able to contact the booker if they are not attending an event themselves, over the telephone for example, in case of any problems with the ticket on the day of the event.
Are Britons able to buy tickets from overseas sellers?
As at every other Olympic Games, the National Olympic Committee (NOC) of each participating country gets an allocation of tickets.
Some countries' authorised resellers are legitimately selling these tickets online.
Some UK residents have been able to buy tickets this way, especially from countries within the European Union.
But Locog has warned UK fans to beware of bogus and unauthorised websites when searching for tickets from overseas sources.
It urged them to use the London 2012 website checker to verify if the seller is genuine.
What is the price range for Olympic tickets?
The best seats at the opening ceremony cost £2,012 and £725 for the men's 100m final, but 90% of tickets sold have been for £100 or less, two-thirds under £50 and about 25% cost £20 or less.
Children under 16 have been eligible to "pay their age" across more than 200 sessions and tickets for over-60s have been priced at £16 at the same events.
Full price Paralympic tickets start at £10 and special £5 tickets are available for children under 16 and people over 60.
London 2012 said three-quarters of the tickets were £20 or less and half were £10 or under.
The ceremonies ranged from £20.12 to £500.
A full schedule is available on the London 2012 website.
Will there be any free events to see?
Yes, there will be events such as the marathon and road cycling where you won't need a ticket apart from for certain sections of the cycle race and the final section of the marathon.