I wish I had a little yellow submarine that I could putz around in. Motorized would be optimal, but I could even deal with foot pedals, as long as it's a submarine and it's yellow. Unfortunately, I haven't been able to find one within my price range, nor a piece of dock space where I could keep it securely stored, so I guess I will have to settle for this, which was featured on ShinyShiny. It's a fully-functional FM radio with a waterproof speaker, is powered by four AAA batteries, and it's designed to float in your bathtub. It comes in black, too, if you prefer your Beatlemania to have a Goth flavor.
P.S.: On a related note, apparently hippies have taken over Capitol Hill. So maybe I will get my real yellow submarine.