Implementation Questions - CONTEXT?!

I've been trying to set up a GTD system for a while and just keep hitting walls trying to figure out what to do.

Collecting isn't a problem, but processing is. I can set up projects, determine next actions, and so on. The big problem I hit is context. Like many of us geeks, an @computer context doesn't work.

Let me explain my life situation. I'm a college student, so a @School context would be useful (or will, when summer break ends), but I don't know what to do for other projects and things. I do web design, am teaching myself PHP, and also write - all things that have to be done @Computer - but that's most of my life. Standard geek problem. How do I contextualize stuff like "Write PHP script to insert data in DB"?

I'm so lost. A Global NA list is just too much. It becomes monstrous, and overwhelming. It was overwhelming to just look at my collection list when I started - and I still haven't finished processing it.

HELP!