DR2B, I have never owned a 1 gal as I firmly believe it's to small for any species to be comfortable. I have however kept a 2.5 gallon with a sponge filter cycled. The trick is more frequent, small water changes. If you do a full water change you will remove all of the beneficial bacteria's food, they will starve and the cycle will have to be restarted from the beginning. As I inferred in my previous post, you have to keep a vigilant eye on the parameters, it's not easy, but not extremely difficult either.
Edit: Forgot to mention that a small bio load (e.g 1 Betta) is necessary for it to work.