I have a Cowboy Studios trigger setup.
It works very well with my 430 EX II. It *does not* do TTL flash, so you'll have to set the flashes manually. If you want TTL flash settings, you'll have to spend quite a bit more money.
The thing I like about the Cowboy Studios setup is that it does not require line-of-sight to work. The flash can be a considerable distance away or even in another room.