MacJournal
For the past few months I have been using MacJournal by Dan Schimpf Software. This is a great Macintosh application that allows you to store data in a Journal form.
Does this mean I am writing a book? No, I am logging all my PHP, ASP and Cold Fusion code so that I can use them again. This application allows you to store the data in an organized way and the find it easy.
For the past 2 years I was using BBEdit, and saving the files in a Library folder. However, this makes searching hard, and BBEdit doesn't support images.
If you do any development on a Macintosh, you should check out MacJournal.