http://www.vmware.com/vmtn/vm/browserapp.html

Obviously you still need permission from your IT guys to install this but it looks *VERY* safe.

It's basically the VMware solution I suggested before but without most of the hassles.

1) This is entirely free other than 300 mb of downloads.

2) The browser comes already set up, you don't need to install the OS in the virtual machine.

3) The browser is Unix-based, making it far harder for any malware to attack. Even if it could somehow violate the security of the virtual machine (something that by itself is very hard to do unless you have opened connections between them--I have never heard of this wall being breached) it would still have to be set up to attack both Unix and Windows.