Hand-held electronic devices that would show action replays and give live updates would be given to every spectator at the London 2012 Olympic Games, the London Mayor Boris Johnson suggested yesterday.

Trips to the Olympic site on the Thames, on specially constructed boats, would help create a "festival" atmosphere in the city and improve the spectator's experience, the Mayor told the Commons Culture, Media, and Sport Committee. The ideas are among several being touted by Mr Johnson to ensure London is a "more friendly, more intimate" and "cosier" host than Beijing was, and to get the whole city involved in the competition.

"One of the things that we were thinking of doing was to have hand-held devices, BlackBerry-type gizmos, that you could be issued with when you come into the [Olympic] park telling you what's going on, or giving you instant action replays," he said. A strict RSVP system for corporate guests would encourage them to return unused but paid-for tickets. Those would then be handed out free to school children, ensuring the spectacle of empty stadiums familiar from Beijing was not repeated.

Mr Johnson said yesterday that, although he admired much of what he saw in Beijing, he felt that the Chinese Olympic facilities were "vast" and "intimidating", with security levels – including spot checks on the underground network – which "many people found oppressive".

The Mayor said London would avoid the "great soulless piazzas" of Beijing and would instead provide a "more friendly event for the spectators".

In August, The Independent revealed that Olympic organisers were planning to host a series of parallel events to mark the opening and closing ceremonies, rather than focus exclusively on the Olympic stadium.

Facing the first hearing of the committee since Beijing, Mr Johnson was forced to give repeated reassurances that the Games would be delivered within the £9.3bn budget despite the economic downturn. Referring to "increasingly difficult market circumstances" and huge "cost pressures", Mr Johnson said: "I'm working very, very hard to make sure that it doesn't go over £9.3bn."

Doubts remain about what use the main Olympic Stadium will be put to after the Games. The capacity of the 40-acre venue will be reduced from 81,000 to 25,000 seats but it is still unclear whether a local football team or athletics club will have use of it.