Bayhoff Software has released SerialBase for the iPhone and iPod
touch. It’s built to work similar to Apple’s built-in Contacts app.
SerialBase is a simple app designed to store your programs’ serial
numbers and other relevant information.

Specifically, SerialBase can store the following information: program
name and version, program developer, tech support email address, user
registration name and/or email address, serial number, activation
code, program web site, and miscellaneous Notes. Using the export
feature of SerialBase, you can export a program’s serial number to
Apple’s Mail app, where you can then mail the program information
right to your desktop computer.

SerialBase costs $1.99 and is available at the Apple App Store