I used Ascendo Data Vault for secure information such as credit card info and passwords. Unfortunately Ascendo only makes it for the Blackberry and the iPhone. And so far I have not found a data vault/locker program for WP 7 that will allow me to import any kind of file from Ascendo DataVault and have it read in correctly.

I highly recommend Sky Wallet for storing bank and CC info on WP7. It supports 256-bit encryption and has a neat little desktop companion. Although it doesn't support importing from Ascendo, it does support text file import / export. I'd be surprised if you couldn't export your Ascendo data out to some sort of external format for use in another app.