I'm a member at TechShop. I'm lucky in that I've got two locations nearby. I don't use it as often as I'd like (kinda' like a gym membership), but it's been great to learn how to use all the equipment. It's especially handy for those occasional needs (metalworking and shaping, for example). The big draw for me is the access to CNC equipment - several Shopbots, along with a Waterjet, plasma and milling CNCs. They don't have super high-end gear, but it's pretty good stuff and they maintain it pretty well. I don't expect to use their woodworking shop much, but if you're a woodworker who has a small apartment with no garage, it's probably a great resource.
It's expensive, but so is buying the equipment that I've used there, and they run specials every once in a while with big reductions on memberships. I also consider it a learning experience, and have taken most of the classes they offer. It lets me know what capabilities are out there. They rent out office space for what I assume are small prototyping houses. The clientele is an interesting mix - I think half the people are making functional things, the other half are making art, with some overlap. I think the access to welding and metal fabrication really opens up some doors for artists. Certain machines get busy as wedding season approaches (the laser engravers crank out a lot of custom wine glasses, for example).
It's a neat place, but not the only such place, as Vocademy says. Google "makerspace" and you might find one near you.