I'm a big fan of NetWorthIQ, probably pretty obvious since I've been a member of that site since early 2007 and I'm one of the most "active" users.
Besides keeping track of our own net worth, I find it very motivating to compare myself to those, in our age bracket, who report net worth numbers on both ends of the spectrum.
While I'm not trying to keep up with the Joneses, I find it helps me focus to see what others have accomplished and how they have accomplished it. There is a Florida networthiq.com profile that exceeds $139 MM. Wowzer!
I'm also impressed with those in my age bracket who are working away at their debts. Many of them, with big debt numbers, seem to be chipping away at big student loans for medical school of law school. I'm not taking comfort in others' pain, but I find that thinking about having $100,000 - $200,000 in student loan at my age to be scary (of course others might find our $600,000 in mortgage debt to be even scarier). And thinking about others' debts strengthens my resolve to stay away from debt and to keep working on our own.