Ok, so some of you probably won't find this that helpful, but here's something I think is rather cool.
All of you should know that in OS X that the terminal command:
$ mdfind *******
where the ******* is your search term (and yes, you can constrain the results using a specific directory, or wildcards) will use the spotlight framework in OS X to find files that contain your search term. That's pretty nifty, and it's fast, significantly faster than the GUI.
The next part of this hack uses a very basic shell scripting thing, that most shell fiends know...
$ mdfind ******* > search.results.txt
Will preform your search just as above, but it will put the results into whatever file you say, and make a new file if it doesn't already exist. That's kind of cool.
Once it's in the file I open the new file in TextMate. With some quick find and replace I escape out the spaces in the file names, and prefix all of the lines with an "open" command, I could probably write a macro that would do this, but I'm lazy, and the opportunity to write a regexp every now and then makes me feel smart.
Then, because TextMate is so awesome, if you just hit ^R (control-R) when you've found a line that mentions a line you're interested in, it will execute the line, and open the file.
As I think about it, you could omit the "open the terminal and enter the command" step and just sort of use TextMate as a sort of de-facto shell, but I have a terminal window triggered to a hot-key that's easy to work from so that seems like the way to go.
Anyway, I think it's fun, and I definatly recomend using spotlight from the command line, rather than the GUI, because it's faster, and I find that having the information about where the file is located is helpful for sorting out files that I know can't possibly be the right ones.