i think surfcam works on linux, but unless you got 10 grand laying around, you might wanna look at something cheaper.
what distro of linux are you running? if you have a deb based distro, check the add/remove application after you enable the 3rd party repositories, and you might find what you're looking for.
another option is to install virtualbox, load XP into that as a virtual machine, and run your software on the virtual PC. its a little slow if you're going to be doing ultra high complexity things, but i found it works nicely for most situations. Just dont draw every thread on every screw and every tooth on every gear and i think you'll be fine.
PS, I heard about an OS called RealOS or ReactOS or something like that thats specifically designed to run virtualized. Its got an ultra small footprint and runs all windows apps. you might look into that if my previous suggestion doesnt meet your speed reqs.
if you try any of this and it works, let me know please. As of right now, I've been dual booting XP/Ubuntu Hardy so I can have a decent OS and still do high quality 3D CAD drawings.