I recently was introduced to Mint.com. It is a money management website where you can track all your credit card, savings and checking accounts, etc.
And I have got to say - I recommend it with 2 thumbs up.
Mint.com supports all my credit cards and my big bank accounts. The only one that it doesn't yet support is a small one from Missoula. Mint.com is secure as nobody but you can access the account data. The visualization options are great too and you get alerts about when bills are due.
The service is currently still in beta (which web service is not - almost seems like an extended beta as mandatory in these days of web2.o). As it matures I am sure it is only going to get better.
I have tried Microsoft Money (too complicated) and Wesabe (liked it - just didn't support all my accounts). Wesabe has one cool feature - it uses social information to label transactions as well as you can ask other users to answer questions you might have about managing money.
On the other hand, Mint.com continuously looks through your accounts and interest rates and gives you suggestions of accounts to which you can move to, to save money. The budgeting options are simple - which makes it nice to use and you get to compare your expenditure to average US numbers.