Big events like the Olympics need not mean building huge capacity, only to have it unneeded and taking up space/resources. How about foldable temporary hotel rooms?
urban planning
How to Make Large Events More Sustainable: Foldable Hotels!

Gordon Brown's Great Eco-Towns Con | spiked
Usually quite a thorny bunch of lefty enviro-skeptics from what I gather (and why no comments turned on eh?) but this piece actually makes sense. My own personal view is that there should be a loosening of planning laws - starting with self-builders (NOT developers), followed by allowing 'eco' houses to be built on farmland and in woodland - and then we can look at greenbelts.
UK Government to Build Carbon Neutral Ecotowns
The government in the UK is planning to build 10 carbon neutral ecotowns of 5000-20,000 homes by 2020. The ecotowns will run on renewable energy and some are hoping to make them car free. When will the US government start this kind of effort.

Making cities ready for an uncertain future
People really want to figure out what to do about the twin dooms they hear are upon them; thinking people know recycling just isn't enough. There has to be some kind of coordinated preparation. This is a book from the Post Carbon Institute about how we can become more ready for peak oil and climate change at the city level. It's meant for planners, city government, and citizen activists who want to try to make sure their corner of civilization has a plan in place.