A trick I learned way back when I started at Cingular who was blocking all non .org and .edu domains (and of course company-relevant websites). Is that I could go virtually anywhere by tagging '?.org' to any URL.

Our network was only looking for the word in there and not actually looking at the real domain. It worked quite well till they paid me to tell them how to fix it.

Possibly this would help, although I don't suggest downloading and installing applications, especially if it's a major company they could press charges if you load any sniffing apps or something for fun.

Hope this helps though.