I went looking for cheap wifi routers that can run OpenWRT and came across the TRENDnet N150 which sells for $26. http://www.amazon.com/dp/B00979B8D8/ref=cm_sw_su_dp It only has 4MB flash and 32MB RAM, but that might be enough. It uses Qualcom's Atheros chips which seem to be well supported by OpenWRT. TRENDnet is marketing it as an "Open-source wireless router for Linux developers and open-source enthusiasts". I'm going to go ahead and buy one so we can play with it and try to get batman-adv on it.