I haven't been thrilled with available filters for the small aquarium but have kept looking. I thought the small tank would also benefit from a canister filter, but apparently I was the only one thinking this. I don't like sponge filters (even though they do a good job) as I don't want a black blob in my tank. No internal filter, uses up valuable space; no under gravel, I might want plants in my ten gallon. No HOB or HOT filter, to noisy and not enough filter room.
Basically I had given up on my search for the "perfect" filter for the small tank when I happened to spot this at Petsmart. Its designed for turtle tanks but claims it will filter up to a 30 gallon tank, which I think is optimistic, but think it would be great for a 10 or 15 gallon tank, heck even a 5 gallon tank. The only negative I have is that it is recommended to sit beside the tank, not underneath it like a normal canister, probably doesn't have enough "oomph" to get the water up with its 4 watt motor.
I prefer this filter as it is larger than most filters for small aquariums, I'd turf the charcoal and biotubes that comes with the filter and use Fluval biological media instead.
I thought you might enjoy seeing this; note: its not in the aquarium section of Petsmart but in the turtle section. http://www.futurepets.com/TURTLE_FILTERS.HTM
A youtube video showing the filter in use in a turtle tank with the spray bar hooked up, would work fine in the small aquarium as well. http://www.youtube.com/watch?v=aXWmiuyOYVc