Mercurial or git?
atiw: I would go with mercurial. 
It just works well with both Windows and Linux (I don't have a MAC).
And like alfred said, hoping is not a good option for you.
I would always go with any tool, that's proven that obscure.
Playing around with it, and testing it is fine if you are a <4 people team.
Anything more than 4, and I think it's time to google "XYZ number of users" and it will show you stuff.If you still need more information to be sure, I think I trust these two, esp recommend the google code link.http://code.google.com/p/support/wiki/DVCSAnalysishttp://rg03.wordpress.com/2009/04/07/mercurial-vs-git/
This one is a little balanced. more like a good info on internals of both. A little too long, and I didn't like the fact that the guy says both are great, in summary. 
I knew that already...pick a side if u write a VS article...or else what's the point.....