Great - I'm looking forward to seeing this soon. We perhaps need a pub with a LAN connection to really appreciate it!
Well one possibility is to set up a Pandaboard ES to act as a DHCP server (for the Pi) and WiFi connection (it has WiFi on board, to use the pub in question's free WiFi [I presume you mean the Hope & Anchor on 11th July]). Unfortunately, although I have the necessary hardware, that is beyond me as it would require knowledge of Linux.
If not then there's always a wireless portable if I can work out how to get it to act as a DHCP server for the Pi - is that easy under Windows XP?