I would be really interested in hearing success stories about finding cofounders online. I agree that a tight founder/cofounder relationship is tough to find, but there seems to be no shortage of good hackers out there wanting to work on exciting things. So maybe its just a matter of finding one of those hackers that you can get along with? Furthermore, I think the "tightness" of these types of relationships are basically proportional to how good of friends these two people would be outside of that founder/cofounder relationship. I always thought the best teams consisted of best friends.