From David Wheeler:
iLicense allows you to organize all of your software license agreements and serial numbers into one database so you'll never lose one again. Simply choose an application and iLicense will pull up its icon and name. iLicense also works for web services that have agreements or activation code's. When you ready to add an agreement iLicense can easily import the license from a file. Still prefer a hard copy? iLicense can print all of your licenses on one sheet. If you like to keep backup's, receipt's or dmg files that your software came with you can simply add them as attachments. With iLicense organizing your software license agreements and serial numbers has never been easier.