Dan
There are services that will give you a shorter URL, if you are on a free host, but that won't help you. They just re-direct from the shorter URL to your actual URL
The URL you are on now is owned by the hosting service. I doubt that they will be willing to re-direct your traffic to another host, if you aren't staying with them.
If you have your own domain, you are in control, otherwise, you are at the mercy of others.
P.S. Take a look at Pair.com, as recommended by a previous poster, I have read good things about them.