Too bad there seems to be no room for SD cards and spare batteries. The top part seems to have room for TV cable and earbuds, not sure I like having hard stuff packed closely on top of my screen though...
There would be a lot of room in the bottom for spare batteries etc if they had made the bottom flat instead of custom shaped to the GP2X. Like there could have been space for 2 batteries on each side and earbuds on the top. And then you add a couple of pockets for SD cards in the top part so they can't damage the screen.