ughhh i am at work and can't check my gmail!! this is torture.
okay, you are going to thank me in a major way for the following information:
* set up an igoogle homepage using your gmail account information.
* go to "add stuff" to add a gadget to your homepage
* in the "search for gadgets" field, type "gmail"
* add the gmail gadget with the description, "An even better Gmail gadget..."
It will show up on your homepage as a little box that just says "Loading..." but if you click on it, it will bypass your network's security and take you straight to your gmail inbox. At least that's how it works for me...
I recommend signing out of gChat, though, just to make sure you don't occupy too much bandwith (i.e. get noticed by the tech guys)