This is actually a really cool idea for a site -- Fitzcairn's Macro Explain-o-matic is basically a web script that reads WoW macros, and will go, line by line, through them to put exactly what they do in plain English. Sure, odds are that if you have a macro already, you probably have some idea of what it does, but if you've ever wanted to learn how to write macros, or aren't sure exactly what the macro your friend emailed to you is supposed to do for your character, you can just throw it in a text field, and then Fitzcairn's script will break it apart for you.
The site will even let you save (with a permalink) and email any macros you punch in -- though I couldn't find a way to browse them, maybe Fitzcarin is working on that. There are lots of resources online to find macros, but not so many to explain them well, so the Explain-o-matic is definitely worth a bookmark for the next time you need a little help.
[via Twisted Nether]