A while ago I was looking for a general tool to store information on the iPhone. I came across Handbase (this has been around since the Palm Pilot days) which I purchased.
Handbase is quiet powerful allowing new databases to be defined and sync’d with a PC. I used it to set up a database for storing all my passwords. This is in-turn encripted via the App.
Now I have discovered Bento for iPhone. I would say that this app would be better suited to most users.
It has nearly all of the power of Handbase but with better functionality and looks. It is also £2.99 as oposed to £5.99 for Handbase.
Bento is still not the tool for creating password databases as it does not include suitable fields.