I've been using one of those BoreSnake things and I love it. I keep it in a small plastic box and take it in my truck to the range, duck blind, etc. I occaisionally spray the front end with kroil and the tail with RemOil. Works great! I'm going to have to add a 20g one and then some rifle/pistol calibers.
Will, I have to agree. Nothing cleans up as easy as my Beretta barrel. The gas system is another matter, not so easy.