When I make Steve's little clown that "walks" down the ladder it has a number of dowels that I round over. I use my disc sander and just round them by slowly spinning them around. You could also just put a piece of sand paper flat on your bench and sand them by hand. Neither of these will give you the consistent look that a router will, as Chief mentioned, but they look good enough for government work
Depending on your project and the size of the dowels used you can get them looking pretty good with a little effort and it won't cost much.
Barry