I track my net worth monthly on NetworthIQ.
This month I'm making an adjustment to what I track by adding my wife's Roth IRA account. I wasn't previously tracking her Roth IRA in the net worth total. Her account wasn't all that high and I don't have routine easy access to the balance figure. So I just didn't bother tracking it. But now she's been drawing cash to fund her Roth which makes it look like our cash is going nowhere so I figured I should really add the Roth IRA into the total. Adding my wife's Roth IRA makes about $15,000 difference to the total net worth.
So while the January 2010 figure is now at $627,348 which is up $10,494 from Dec. 2009 that includes a bump of roughly $15,000 from adding my wifes Roth IRA to the tracking. So the net worth is really down $4,506 in January.
There weren't any major changes in our net worth otherwise. Basically the value of our real estate dropped some and our cash balances dropped a bit. My retirement was up some not counting the addition of my wife's Roth IRA figures.