Here, BBC Sport assesses the impact of the Olympic bid launches in London, Paris, New York, Rio and Moscow.

View from London Bryn Palmer

The location might have been grandiose, but "compact" was definitely the buzzword of the day at the launch of London's bid.

And even in a venue like the Royal Opera House, the 300 VIPs watched proceedings from a room that looked more a university lecture theatre.

Barbara Cassani is keen to promote the idea of a lasting legacy

No-one could have left Covent Garden without being aware that 17 of the 28 Olympic sports would be within 15 minutes of the athletes village or seven minutes from central London.

It may be the biggest single event in world sport, but organisers are keen to emphasise the proximity to accommodation for athletes and spectators alike.

The official presentation started 20 minutes later than scheduled, but as each bid leader took the stage, the soundbites came thick and fast.

Barbara Cassani stressed the need for "excellence without extravagance", while the theme of a "lasting legacy" for London emerged at regular intervals.

With all the proposed venues trailed beforehand, there were few surprises.

But it is clear London will trade heavily on its heritage in the bidding process, Paula Radcliffe delivering a message on the "inspiration of London landmarks."

Tony Blair indulged in a quip about the delights of watching beach volleyball on Horse Guards Parade, and managed to say 'tremendous' and 'fantastic' several times in quick succession.

Cassani's smile remained fixed throughout, swatting aside concerns over transport and confidently declaring "Our stars are aligned for success."

Stage one complete, the hard work now begins in earnest.

View from Paris Matt Williams

Paris may be favourites to land the 2012 Olympics but its bid team seems intent on playing down the city's chances.

While their London rivals unveiled their plan at the Royal Opera House, the Paris campaigners took up a relatively small room on the first floor of the Eiffel Tower.

Yet, essentially, both bids are very similar.

The Parisian public transport structure is the envy of the world - and they plan to improve it even more before 2012

The International Olympic Committee wants to turn its back on grandiose projects - and so Paris and London have put great emphasis on how easy it will be to get from one event to the other.

The obvious card Paris holds over its rival across the Channel is transport.

The Parisian public transport structure is the envy of the world - and they plan to improve it even more before 2012.

But it is still too close to call - and we all know that strong technical bids do not always win.

Paris learnt that lesson last time against Beijing.

View from New York Jane Standley

Paris may have held its ceremony at the Eiffel Tower, but New York's pitch for the 2012 Olympics started on a decidedly low-key note.

A press conference had to suffice as the official launch of the campaign - unusually understated for the Big Apple - but New York is quietly confident.

New York's finest will play a key role in making the Games secure

It is pitching hard on the fact that this is the world's most ethnically diverse city and that every nation can have a home crowd to play to.

Tourists will feel at home here, too - and they already have more than 66,000 hotel rooms to choose from.

New York is selling its tourist attractions in the same way as its big city rivals, but few of them would be used for the actual games.

And there would be no swish Manhattan address for the 16,000 athletes, although the waterfront regeneration plan is being touted as a major part of the bid.

So is the transportation plan, with bidders claiming there would be no gridlock and no disruption.

Security would also be good thanks to the NYPD.

And the cost? $3.6bn - none of it coming from the taxpayer. Instead, ticket sales, media rights, licensing and sponsorship deals would cover the cost.

Now that could turn out to be a very exciting part of New York's package.

View from Rio de Janeiro Steve Kingstone

Sitting here on Brazil's world famous Copacabana beach, it is easy to see Rio de Janeiro's main selling point.

And that is the city's stunning natural beauty.

Rio is one of the most dangerous places on earth but Rio is not the risk that some might think

None of the other contenders can match the combination of sun and sea, sand and mountains.

The main reservations here are about security.

Statistically, Rio is one of the most dangerous places on earth. But it is not the risk that some might think.

The city is hosting the 2007 pan-American games.

Preparations are going well and that means much of the infrastructure for the Olympics is already in place.

View from Moscow Steve Rosenberg

Moscow's bid was made public in a small room at Luzhniki Stadium.

There was no razzmatazz, no music; there was no promotional video; and no Russian Olympic champions putting in appearances.

Moscow last hosted the Games in 1980

There were no senior Russian politicians on hand to back the bid either.

Moscow's bid is low-key to the extreme.

No pomp, but that's the whole point - the Russians say their plans are by far the most economical.

They won't need to spend a huge amount on creating Olympic facilities - many are already built, left over from the 1980 Games.

It's that recent Olympic experience which Moscow believes gives it the edge over the rest of the field.

Mind you, it's hard to picture a Moscow Summer Olympics - when everything around you is covered in snow and you're frozen to the bone.

To be fair, though, the summers here are sweltering.