The whole business model of copy-protected games just sucks. And more and more companies are realising that.
Eg. the number of online music stores selling DRM-free music is ever increasing... As are their profits. It's what people want, and they're willing to pay for freedom.
Also, the number of commercial games that are completely free and are sponsored by in-game ads is also increasing. If people have to pay for a game, they expect added value over a pirated copy. Most pirated copies, however, have added value over legal copies. They're generally not messing up your computer, you don't have to carry around a pack of DVD's and some other advantages.
So, instead of wasting your time and money on copy protection, you'd better concentrate on added value. I think that's something Nintendo, of all games companies, understands best. Their games are pirated by the mass, but they're still selling tons of merchandise, like eg. the whole Pokemon stuff.
Well, I can understand that for a games scene as small as the gp2x's, creating and selling merchandise is far out of reach. But there are other ways to attract legal customers. Like hiding features in the game and sending clues around in regular newsletters. The newsletters will be copied, but legal gamers will be the first to read them. Send free addons to registered users.
If you really want to copy protect the game, use what the "S" in "SD" stands for. Or develop a dongle, the GP2X has enough I/O on the ext. port for that. You could equip the dongle with some kind of WORM memory and move random parts of the program code to it, so every dongle/software combination will be uniqe (you could do the same with the SD protection). But someone will manage to merge the parts in an independant executable. And be prepared that you'll never make any profit since protection will cost more than it will produce.
