Using Internet Connection Sharing (ICS) on a PC would work. It would require a wireless adapter or an extra NIC port for a second network connection and would need to be left on. That's not a great solution. Picking up a second router may be the best way. It wouldn't need to be a high end model, just have decent wi-fi performance and be able to run DD-WRT. There should be some deals around for Boxing Day. A used router might also be an option. A wireless router should support the wireless N standard. The WRT54G is limited to the G standard which is outdated for newer devices. The newest routers support AC but they are still a bit pricey.