Download KeePassBB, Encryption Tools for Blackberry
KeePassBB can use both the AES and Twofish encryption algorithms just like the desktop version. You won't notice the difference between the two algorithms on the desktop but on the BlackBerry, AES will be slightly faster because of the native implementation. Also, the number of key encryption rounds can greatly affect the speed at which the decryption process happens. 600,000 rounds on a PC will be hardly noticable but on the device it will be unbearably slow.
The desktop version of KeePass has the concept of keyfiles. These are files which contain a key required to decrypt your database. Presumably you keep the keyfile on a USB stick that you can remove and physically secure. Some users rely solely on the keyfile while others use it with a password. When used in conjunction with a password, it means that an attacker can't decrypt your database even if he has the database file and your password.
KeePassBB also can use keyfiles but you must be VERY careful. If you secure your database with ONLY a keyfile, anyone who picks up your BlackBerry will have access to your database. Always use a password in conjunction with keyfiles. If you must use keyfiles alone, make sure your BlackBerry has a password and the timeout is set for the shortest timeout possible.
You can set a default keyfile in Options. You can also set an option to hide the keyfile on the password dialog.