Sorry if it's old news for some of you guys, but I just found out that using MacFUSE and sshfs makes it super easy to use TextMate projects/tabs with files on remotes servers (as long as you have SSH access). I know the question comes back once in a while on here, and I for one was never really satisfied with the workarounds people suggested...
This solution makes it really dead simple to get access to all TextMate Project features... I wrote up a little blog post with the details if someone's interested:
http://minimaldesign.net/blog/workflow/remote-textmate-projects
Hope it helps :)