Program like Port Magic

Does anyone know of a program similar to port magic. For those of you that don't know it is a program that automatically maps ports to your computer if you are using a router. I have the version that comes bundled with AOL and it works great. The only problem is that on some programs it only maps UDP connections when they are using TCP. I am not sure if this is a glitch or what. Anyways, Pure Networks Port Magic is out of the question. I was just wondering if anyone knew of a program thats does the same thing. I googled it but didn't come up with much. BTW, I am using a linksys router so I need one compatible with linksys. Thanks!