I just found this article
For years man has wondered how do I get Internet on my Xbox 360? Today you will need to look no further! I have found a way to have a Internet browser run on the Xbox 360 without no illegal modifications! You must have the following for this to work:
- An Xbox 360 with a Internet Connection (Duh!)
- Windows OS (XP SP2, Vista)
- Windows Media Center hooked up
Steps to follow:
- Install Windows Media Center Extender on your Xbox 360 using the following guide
- Download and install this program
- Once the program is installed check to see it works fine on your PC by doing the following:
- Open up Windows Media Center
- Scroll over to “Online Media” and enter the “Program Library” Menu
- The first program you see their should be called “Browser”, enter it and test it out!
4. Repeat the process on your Xbox 360
Their you have it, a web browser for your Xbox 360, have fun! I have not tested out everything in the browser yet but at least it works! I don’t see why Microsoft would say anything since we are not modifying anything.
The “PC world” knows about this program and its wonders, so I am assuming someone may have tried it on a Xbox 360 already. But a majority of Xbox 360 owners are clueless.
Just a tip: To type press “Y” to open up a virtual Keyboard, maybe a real one will work as well.
Please Digg this, and if you like it then please donate to the site 
Note: Now please stop hassling Microsoft over something the 360 already has
Update 1:
It seems like this doesn’t save files, but I have only tried one site so maybe others will have better luck, this means you are safe from spam, viruses, etc
http://segafanclubblog.com/2008/05/04/internet-on-the-xbox-360/
