Much of investing performance comes down to patience and a long-term outlook. Overtrading will kill you with fees (but your broker will love you), and trying to time the market is almost guaranteed to reduce your performance. However, I still enjoy monitoring my net worth, and it lets me feel like I'm "doing something" when all my investments are in place and just need to be left alone.
I've just started recording my net worth info using www.networthiq.com. I already I track my networth daily using a spreadsheet (data from various online accounts daily). I used to use Quicken, which was great for budgeting and handling the calculations for Capital Gains Events (ie. share sales) as it handled individual lots very well. But since getting married and starting a family I didn't have the time to keep Quicken regularly updated, so I've had to manually do CGT calculations at tax time each year.
I've installed the 2006 version of Quicken (it was free with last month's Money magazine), and so far I'm keeping up to date. Entering 20 years of share transactions will be this years major project! I'm still working out how to record my property and mortgage info in Quicken, but getting it to only count half of these values in my networth report (I only want MY networth, and the property investments and mortgages are in joint names with my wife).
I also want to write some PERL scripts that will automatically login to all my online accounts and grab the relevant daily information and display in one place - this will save me logging into half a dozen accounts each day!
Anyway, although it's a bit redundant I'll update monthly data from Jan '03 to the present into NetWorthIQ over the next few weeks so it can be easily displayed for this blog. I'm not sure that it will be of any practical use to anyone, but in the Blogosphere I think having an 'Open Wallet' gives you cred. It's always nice to know where someone writing about investing is 'coming from'.