At one point, the Textmate website mentioned that a follow-mode-like feature was in the works, but 1) I can't find that mention anymore, and 2) even if it is, I'd rather not wait forever for it.
I believe this plugin does what you want: https://github.com/atbell/SublimeSynchroScroll
I don't even click tabs that I have open any more, I just hit Apple + p and start typing say g-l-o for global.css and I know its there, hit enter and voila.
Like you say, multi-platform too, so I get to use it on my little Ubuntu netbook and on my iMac. Love it. Really should buy a licence.
Edit: Scrap that, rush-read - CntrlP doesn't beat Sublime's Apple+P. Honestly, try it and you'll see what I mean.