FWIW, I put together a quick howto for patching OpenWRT 8.09 to use ARPNAT, allowing it to act as a WiFi client bridge for wired devices.
http://projectgus.com/wireless-client-b … h-openwrt/
The patch originally comes from the Gargoyle router project.
So far I've used it successfully on a Fonera and an Asus WL-500gP. I've taken a few performance measurements, and while there is a performance cost from doing this it doesn't seem excessive (I haven't taken the time to compare it with using WDS or IP routing, only with directly accessing to the router.)
IMHO, this is a very easy way to join several wired segments into one large single network, if the wireless devices aren't all happy speaking WDS (or if you don't want to lose half your wireless bandwidth between nodes.)
The only hassles I've had are related to DHCP, and are described in the blog post.
Hth. I also hope the OpenWRT devs consider formalising ARPNAT support (even if only as a config option) in the future. Patches submitted in the past have been rejected outright, claiming performance problems.
(Last edited by projectgus on 25 Mar 2010, 10:00)