One key problem with lots of the project proposals was a differentiation between your goals as site creator, and the kind of experiences you wished to provide to your users. Make clear in each section the whose goals you are attempting to meet in each section of the plan.
Similarly, there was a lot of talk of technologies that can be used without a motivation as to why to use them. Google maps visualisations might be cool or whatever, but there is also a real need to justify why to use it other than that “it is there”. There has to be some value add to your aesthetic or commercial goal to motivate using it.
Prioritise! The bulk of proposals were for project far more ambitious than could be delivered in the timeframe. That’s fine, but make sure that you are clear on the priority of your goals, and that you have a plausible fallback plan in the face of (inevitable) difficulties.
Finally, a project proposal is a pitch document. Make sure that you are aware of its need to be persuasive and to present your idea as worth investing time in. Don’t get bogged down in the technologies you will use any more than necessary – they might be how you will implement them ,but they aren’t what makes your project worth doing.
Now, one final some resource that springs to mind from reading the assessments: The form generation tool that google provides – that dumps data straight into a google spreadsheet for you to use, mashup-style. I think that would be really handy for a number of you getting punter surveys created.