Turning a Linksys WRT54GL Router Into a VPN Server

Ever need that spec document or need to check into Subversion when you're at home? I find myself in that situation often, and the best way to access the office is via VPN. Using a Linksys router, the open source DD-WRT firmware and OpenVPN client, I now have a full featured VPN appliance. Setup was a little convoluted, so I've posted the process I went through to make this happen.