What about “Command T”?
In TextMate, cmd-t opens a ‘find file’ dialog, letting users type a few characters of the name of a file in the project and it’ll “drill down”. This is extremely nice for opening files quickly without using the mouse.
Option 1: PeepOpen (most users)
If you have a reasonably modern Mac, you’ll want PeepOpen: https://peepcode.com/products/peepopen. Go buy it right now.
Option 2: The poor sad unfortunates with 32-bit Macs
If like me you use a 32-bit (original) Intel Mac (non-Core 2 Duo), you’re hosed: PeepOpen relies on MacRuby which relies on 64-bit. You might be able to get a version of MacRuby compiled to work under 32-bit (opinions differ as to whether or not it’ll work), but the short answer is “lovers of adventure only”.
So, you can use cmd-d to open files by name; be sure to check “Find all Matches” and, optionally, “Match Wildcards”. This isn’t exact TM cmd-t behavior, but it’s close when you can’t use PeepOpen.