I would never suggest you try to circumvent your IT department. Nope, not me. And I would never dream of doing such things myself. But in the interest of full disclosure, I would be remiss if I didn't tell you about an interesting article published in the July 30 Wall Street Journal, Ten Things Your IT Department Won't Tell You. You might want to read it, oh, just for the entertainment value, or if you're looking for something to do on quiet August work day.
The article approaches each workaround by explaining the problem, options for a solution, the risks you take if you choose to use the solution, and suggestions for how to use the solution safely. You may particularly like "How to Visit the Web Sites Your Company Blocks", since research can sometimes take us places that might be, how shall I say it, somewhat unsavory. One of their solutions is to use Google's translation services to do an English-to-English translation of a blocked web site by entering http://www.Google.com/translate?langpair=en|en&u=www.blockedsite.com. (Replace the "blockedsite" url with that of the web site you want to visit.) Very clever. In theory only, of course.
You may have a legitimate business need to email or receive large files, in which case, you might be interested in the tip on how to send giant files. (YouSendIt is one option.) Accessing personal email on your Blackberry could have it's uses. But I won't even go into detail on installing unapproved software, how to store work files online, or how to look like you're working.
You didn't hear it from me.