I've just finished a 30-day trial of this service, enjoying free fillums to the tune of 40 quid, from the cheapest local rental place.
I've pulled this stunt a few times, of course, but I must say that if I had a normal income, I'd actually carry on with this one. They have an excellent selection (lots of world cinema and indie stuff), they're prompt, and generally very satisfactory, so if you're thinking of joining one of these schemes, check it out.