In this article, I showed you how I set up a hotspot using two routers, a vintage PC with two NIC cards and m0n0wall software. m0n0wall is quite powerful, and I have been pretty impressed by its offerings, especially considering I was able to use it to set up a pretty low-cost Wi-Fi hotspot for my stingy coffeeshop-owning friend.
I haven't played with m0n0wall as much as I'd like to, but it even has the ability to shape traffic going through the m0n0wall box. Using the Magic Shaper Wizard of the m0n0wall GUI, you can do such things as set P2P traffic to the lowest priority, or even set things to share bandwidth evenly across all of your LAN users.
If you run into problems, or have the itch to play with some of m0n0wall's advanced features not covered in this introductory article, the good news is that m0n0wall has a very active e-mail support group that can help you support your newfound m0n0wall habit.