the disconnected webgeek?

My PC has been giving me problem lately. I built this thing myself, so you would think that I would be able to fix it. Unfortunately, I've narrowed it down to a problem with the motherboard, CPU, or video card - none of which is an easy fix. The video card would be first choice for replacement, but what if that isn't the problem? At what point do we say, "hey, I only spent $300 on this thing so if it lasted me a few years, I should be able to trash it without a sour conscience."

I've actually been thinking about moving my setup to a flash USB drive. Yes, as a web designer, this is a bold step. Instead of carrying a laptop bag to the library for example, I will carry a keyfob. When it comes to benefits, there are many. Among them - cost, maintenance, upgrades, tech support, virus protection, etc, etc. Potential problems include incompatible software, scheduling conflicts, other users hosing up the computers at the library, and the idea of depending on a government entity for my income. Not to mention how lame it might look to clients if I show up with a keyfob and ask, Can I plug into your PC?