I use PhatNotes for protecting info. The program is designed as a database, and that's what most people probably use it for.
I create notes, or paste passwords, credit cards, etc. into notes, and then password protect them. The data is encrypted using the password as an encryption key. The password itself is also encrypted, according to the documentation. So it seems pretty secure to me.
Unlike Resco Explorer, you don't have to go through the process described in previous posts. However, the program isn't useful for encrypting anything except data entered into the program. As far as I can tell, this consists only of text. So it can't encrypt an Excel file, for instance.
Anyway, the program comes free with Pocket Informant, or it can be purchased separately. There are basically two versions - Lite and Standard. The Standard version allows you to sync your notes with your desktop PC. Pocket Informant comes with the Lite version. Here's the link, if anyone is interested:
http://www.phatware.com/phatnotes/