1Password is the gold standard when it comes to wallet apps, safely and securely keeping your passwords, account numbers, credit cards, and any other details you want locked tight in a digital vault. It’s available on Mac, PC, iOS, and now Windows Phone 7. The whole shebang syncs over DropBox, allowing you to keep all your details linked over multiple computers.
The best part is that it’s completely free, but the desktop editions will cost you.
Here’s the official description:
Get access to your logins, accounts and other private information created with 1Password application on your Mac or PC ! Synchronize the data on your phone with your computer through Wi-Fi or Mobile Networks. Store securely all your private data on the phone and carry it with you whereever you go !