At Elevator Up I spend roughly 90% of my time buried in TextMate coding in Ruby. Initially I used grep when searching for text out of command line habit. I also toyed with TextMate's built in searching, but that took too long, especially when I froze Rails.

Then I came across ack. All I can say is wow. I'm not a big fan of perl, but this little script does a great job. It even ignores those pesky .svn directories.

Give it a shot, I use the standalone version which is just a big perl script to toss in your PATH.