One of the best kept secrets of OS X 10.4 Tiger’s release is a little application called Database Events. Located in /System/Library/CoreServices, the new application was given barely passing mention on Apple’s site.
Database events gives you the ability to create databases, records and fields on the fly, making record keeping much easier than writing flat text files. The program requires sqlite, which you can get via Fink, FinkCommander, or at http://sqlite.org. I suggest using one of the Fink alternatives, as the program(s) are already compiled and ready to install.
You can find a good starter tutorial over at MacTech, thanks to our former MacScripter admin Ben Waldie.