Cheap car hire spain?

Anyone know of any good sites for car hire in spain for August 2007? Pickup and return airports undecided as yet, if we go with ryanair, the car hire through hertz is very cheap, coming in at 200 for 10 days, but it's 350 if we don't use ryanair airports, so my question is - does anyone know of any other providers?
Thanks.

Try this. It's a comparator site.

try carjet.com

Check out the relevant key post, too.

As this is such a common query, I'm locking this thread to avoid duplication and copying europhile's post to the thread above.