If you occasionally need a trailer to haul stuff in (like spare parts for your backyard Transformer or something), but can't afford the garage space it will require, you might want to take a look towards Tow-N-Stow. A car-towed trailer, it can easily convert into an upright storage unit that you can tuck away on a quiet corner of your garage.
Designed for moderate hauling needs, the Tow-N-Stow can be easily attached to any regular vehicle with a Class 1 trailer hitch. It sports a wide-open deck (simply pull out the removable top doors) to handle unusual sizes of material, an adjustable tailgate to fit in longer items and enough stability to manage up to half a ton of load.
Once you're done with the day's towing requirements, simply sit the trailer upright, retract the wheel assembly, fold in the tow bar and it instantly transforms into a closet. You can use it as one large upright container or a compartment cabinet (by simply adding the optional shelving system), with enough space to fit in a lot of the junk in your garage.
The makers claim that the Tow-N-Stow is watertight too, which, pretty much, gives you the license to fill it up with water and lounge in it like a mobile bathtub. Even better, you can do that while it's hooked up to a car and rolling down the highway. How cool is that?
Folks interested in hauling stuff and bathing in a tub outdoors can get the Tow-N-Stow for $2,495.