Granted, it's not very big (it measures only 2.5 x 5.5 x 5.5 inches), but it will eventually get the job done. The Mini Cleaner Robot Electric Vacuum is powered by three AA batteries and its transmitter is powered by two AA batteries (not included). You can control its movement backwards and forwards, and it makes smooth turns so steering isn't an issue. It also has robot arms that actually bend, and the transmitter has a belt clip and flashlight so you don't need to get up to turn on the light to use it. There is a removable dustbin attached to its back that must be emptied periodically.
Here's the only bad thing: it's listed as being on sale for just $9.95 US (down from $25.00), but it is out of stock. That, and a Roomba this certainly is not.
Source: Gadget Find