I would suggest we could start a thread like this once a year, maybe at the beginning of the summer or whatnot. The reason I say this is that I am extremely interested in the offers listed here, but I probably won't have time 'til next summer to actually apply for any of them. If I knew at the beginning of the summer (or earlier) what offers were out there, I would be able to apply to a lot more of these offers. Just a thought :).
I agree that a repeat of this post would be much more helpful around February. However, if the students are able to work remotely, then any time of the year works fine.