I got a nice aluminium hybrid from the dump, sorry - recycling centre. Its a Decathlon Triban, nothing special, but free.
I recycled it. And now I'm cycling it. Spent £4 on brake pads from tesco, £2 for a puncture repair kit, £0.99 for a pair of lights mislisted on ebay, £5 for some plastic mudguards, £2 for a lock. Went back down the dump with some tools and recycled a better seat and pedals. Now looks the dogs and rides well so I'm now using it to get to work and back.
Also found an old 80's Falcon Lazer road bike - lovely machine. This one needs more fettling so is a bit of a project.
If you play your cards right and your local dump isn't too HSE Crazy, there are bikes waiting there for you too.