One of my favorite iPhone applications, SplashID (US$9.99, iTunes link), just got a major update to version 4.5.
SplashID is a wallet-type application that stores all your passwords, logins and account numbers in one convenient location. I am a fan because I'm a longtime user of the desktop version of SplashID on Mac OS X which has 256-bit Blowfish encryption and a nice UI.
Version 4.5 includes the following improvements:
Up to 2x faster loading times for power users with many records
Enhanced user interface with simplified navigation
Improved search and look-up functions
Number pad login
New browser window to make log-in to websites on the iPhone easier