Near and Far

http://www.travian.us/  This is a game I'm starting to kinda like.  It's a good background game, since every event is on a timer, and also there's no time limit… so you can leave it running or come back to it the next day.  You build up your little village and upgrade all the lands and such, and thereby … get stuff.

Kind of like a cross between the minicities:  http://skullxia.myminicity.com/

And the D&D Tiny Adventures on facebook: http://apps.new.facebook.com/tinyadventures/

But there's a bit more stuff to be done/choices to be made.  It's good if you just want something to check in on a couple times a day… not if you're looking for something extremely involved.