Yes, better:

An application/website privately hosted (only accessible from the Summit network) that allows to search for people, view their picture and message of the day ("I'll be having lunch under the big oak tree"), and better than all, a "Show on map" link, that allows you to view their current location inside the complex.

This could be relatively easily achieved on a few levels, GPS if active, or more universal: by mapping the location of wifi routers and matching the one they are currently connected to.

Also, a big advantage would be to have an intra-Summit communication system, either text or voice, or both. The big issue this year was everyone had to track a load of people, and it was a bit of a hit-n-miss game to know who had a working phone number, what their skype/gtalk account was, etc. That or just put the gtalk username on the profile with an "IM me" link.