Sounds like Freecycle. Started a couple of years ago in the States. Spreading rapidly. Basically simple Yahoo Groups so easy to sign up. There are usually local groups, you can belong to any close to you. Rules include: No payment, Nothing illegal or offensive, no livestock, no weapons. Designed to save useable stuff being thrown into landfill when it may still have some use left in it or could be recycled. You can post one of four messages, eg:
Offered - A Thing - Oxford
If someone collects it, you then post-
Taken - A Thing - Oxford
or
Wanted - Whatever you hope to get - Cambridge
If you get it, post-
Received - Whatever you hope to get - Cambridge
You can write a little description in the message. I've seen (slightly ropy) cars given away, garden tools, bikes, mobile phones, furniture, sheds, toys etc. Some of it is little more than scrap, but some is good. I've given away surplus plants from my garden, spare car wheels, light fittings, motorbike spares. I've requested odd items/spare parts for obscure cars, and often been given them.