This worm farm was my first Mother's Day gift, seven years ago, and is still going strong. It's a worm swag type of worm farm. These type of worm farms hang from a support (in this case the patio beam), and have the advantage of not being readily accessable to vermin like mice.
It is also great in that it is easily moved around. This position is great in winter as it's close to the back door (which is near the kitchen), gets some winter sun (worms tend to slow down a lot in winter and is semi-sheltered. But in summer I tend to move it to another spot in our yard, that has full shade as the West Australian heat can be a bit much for my worms.
You really don't need to buy fancy or expensive set ups to have a worm farm. Those black can-of-worms are great if space is a problem, and are easily obtain cheap from the newspaper. However the best worm farm I've seen is one made from an old fridge. It was just turned on it's side, air holes were punch in the lid (the fridge door) and a pipe/tap was fixed to the bottom. This set up had the advantage of a greater amount of surface area, meaning scraps could be spread over the top and the worms could spread out and do their job. If you just dump scraps on top, it takes the worms longer to work their way through, meaning the scraps will start rotting and this is not what you are aiming for.