Here's a quick tip for you if you're working with the TextMate project feature.
If your project has a lot of files and folders (like any Drupal project has) it's a tideous job to browse to the file you're looking for.
But there's a quick way to do it. Command + t gives you a "Go to File" dialog. There you can start typing the name of a file. All files with a filename matching the letters you've typed so far start popping up. If the file you want is at the top of the list, you can click Enter and the requested file opens up for you!
Once your file is open it might be a pain in the ass again to go to the right section. If you know the function name of the section you were looking for, you can use Command + Shift + t to get a "Go to Symbol" dialog. You can now start browsing your functions in the exact same way as in the files example mentioned before.
Mind that it's a "Go to Symbol" dialog. So in your programming language or file format some other stuff might pop up in the list.
It's like spotlight for TextMate.