hack my work computer to get web browsing capabilities

[Roswell]

I just started a job and found out I would not get web browsing capabilities. Since my job is a 6month contract, I am considered a "temp", so I have severely curtailed internet access. I have access only to the company website, and the websites of a couple other companies in the same industry. Everything else (google, yahoo) brings up a "Websense" page that says "this page is blocked"

Is there some way I can get web access? Is it possible to do without an administrator account? They are running Windows and have a LAN. I dont know much about networks but I can provide more specific info if asked.