Okay. . .
Sure, go get one of those nice cheap black plecos at Wal-mart. . .it'll eat all your algae real quick! It usually gets over 2 feet long, but don't worry, if your tank is too small or you don't feed it, it'll just die before it can get too big and cause problems. Maybe it'll just 'grow to the size of the tank' and stay 3 inches long forever.
Is that the kind of information i should be giving out? Many people are not aware of the needs of plecos because so many of them are touted for their algae eating abilities, completely overlooking their other needs and requirements. You can't get a clown pleco for algae control in a tank with no wood, you can't get a common for a 10g, you can't get a vampire and try to just feed it veggies. you shouldn't get any pleco and expect it to just eat the algae. if you like plecos, do some research and get one. if you have an algae problem, do a water change.