Yes, PPC 2003 has Terminal Services Client which runs your Pocket PC like a stripped-down version of Remote Desktop Connection for Windows XP. I was using my Axim to Remote Desktop into my home PC 5 minutes ago from my friend's house across town (and am posting this reply via my Axim at his house as well).
FYI: ikehiker has a walk-thru for configuring wireless activesync, and in it he suggested making a few global network setting changes. Until I went through his walk-thru I had trouble connecting to web resources through applications other than PocketIE (even in PocketIE if it was to a port other than 80), but since the walk-thru I have had no problems running Terminal Services Client or any other apps for that matter, except Pocket VNC.