You can force carb one 2.5g keg in the fridge, and naturally carb the other at room temp. I don't know about just storing a keg at room temp after filling/purging with co2??? I wouldn't think that would be a problem, but it won't be carbonated unless you keep it at a very high pressure. It will carb after cooling in the fridge though. How about a dorm fridge? Replace an end table next to the couch with a dressed up dorm fridge with a two tap tower on it..... Just cover it up with decorative wood to match your other furniture.