Are there any good wireless (radio) controllers for the PS2? I need one that is non-directional but it doesn't have to have a great distance, as long as it'll still work with the PS2 behind me.

You have the Ultimate 2.4G Controller, the Ultimate 2C Wireless (which we reviewed earlier this year), and this one: the Ultimate 2 Wireless. Okay, so maybe it's not that straightforward after all.