the fish r fun is a 5 gallon, and is occupied by a betta (just noticed my profile wasn't updated, it's all updated now!). the betta in my avatar in fact (evil beastie Damien).
i have 1 5 gallon, 2 7 gallons and one 7.5 gallon. all occupied by bettas and all in my bedroom, the buzzing of filters is enough to drive anyone bonkers!
also, if you're worried about having chemicals around the house, do the cycle with fish food, i set the tank up, gravel, filter going, etc, and put a large pinch of pellet food in. and keep adding every now and then (i'm really not very structured when i cycle!) and keep checking ammonia and nitrate/ite levels, it'll take between 2-4 weeks to cycle, but it works! make sure you syphon the gravel when it's done though, lots of mouldy food hehe!