Vote "no" on Sunday.
Reintroduce the drachma and ride out the immediate pain. Yes, there will be hardship in the near-term, but in a few years, Greece has significant economic expansion to look forward to. Just look at Argentina in the middle of last decade, after defaulting in '03. And better yet, such a course means the reclaiming of sovereignty from the banks and bureaucrats of the thoroughly undemocratic EU.
EDIT: This is a topic which really interests me, and which I've been following closely for a few years now. Let's start using the #greece tag to talk about it more.