I would echo these sentiments. Sachin and I worked on Posterous.com remotely (I was in Mountain View and he was in NYC) for the months before we applied and were accepted to YC Summer 2008. We could work independently for long stretches and get large pieces of functionality done fast just over IM.

In fact, we've found this summer in Cambridge that the times we've been really able to crank out code are the weekends when one of us is traveling and one of us hangs back at the ranch. Complete control over distractions = gigantic productivity boost.