Laugh!
If you take that Ubuntu install to DefCon and connect to the network there, every place you connect with/to authenticate to/with will be endangered. All of the sites you visit irregardless of protocol (encryption) will provide login/password and URL to others listening and MITM'ing. A VPN is your only partial protection (depending on what your using - no PPTP and easily encroached router firmware). Just do DefCon,there is enough to do, write about and learn while there. If you must work, get a room across town (in a cheap fleabag and drive over) although it should be noted that ANY protection you would make for DefCon needs to be made EVERYWHERE or you risk pwnership.
Someone brought a huge demagnetizer to DefCon 6, carrying it around in their backpack; everyone was stranded since they couldn't pay for their hotel or food, taxi's as about 800 cards were wiped.