Why would you need to chain your dog?
Crate train your dog or provide an adequate sized kennel. Crates are quite cheap as well and you can always find them for damn near free on craigslist. Kennels are a little pricier, but if you're to lazy to train or feel that a crate isn't for you they're the next best thing.
Here's a great kennel at an amazing price:
http://www.samsclub.com/shopping/nav...&ci_sku=330749