I wish I could find a way to force XP to use different resolutions for different users. I figured that would be pretty standard by this point, but I can't make it work. Changing resolution in 1 profile changes it for all. Sorta destroys the concept, eh? : /
http://www.12noon.com/reschange.htm
($499 for a commercial license lol, free for personal use)
Make a shortcut in the Users startup folder (C:\Documents And Settings\<user>\Start Menu\Programs\Startup) with the right command line options.