One very useful feature of Texmate that few people seem to know about is Textmate Footnotes. It’s a Rails plugin that adds this menu at bottom of your pages:

Textmate Footnotes Menu

When you are testing your app, you have links that takes you directly to the contoller, view, layout, stylesheets. You can also see the session, params and log for the current page. If you get an exception in your action, each line of the stack trace is turned into a link, taking you right to the file at the correct line where the exception occurred. If you haven’t tried it yet, what are you waiting for?!