What wireless external hard drive would you recommend?

I have a Macbook with a 2.4 GHz Intel Core 2 Duo processor and a 250 GB hard drive that is quickly filling up. I would love to get a time capsule but that’s just to much money to part with right now. Anything similar would be nice but the wireless router isn’t necessary. I’m hoping I can find something at least 500 GB and maybe in the neighborhood of $200.

Any Ideas?