The USB wifi card I bought (ChiefMax RaLink RT73) needs some special cross-compiled drivers to put the wifi in master mode in order to act as an AP. So i gave up that route and tried making it an ad-hoc peer-to-peer access point.

This (kinda) worked! but only connecting with another Linux computer and even then, NetworkManager’s DHCP screwed up the subnet mask and that needed to be set manually.

Trying the same in Mac OS X and Windows XP was a colossal failure. Mac OS X refuses to even accept a DHCP offer from the openmoko (openmoko is using busybox’s udhcpd) and basically same for Windows: it gives itself some crazy nonsense IP.

So best option is still to get some magic USB wifi card that can be set to master mode from the openmoko using the drivers already in the kernel. I’m not really sure at this point which chipset would do that.

Either way, I think windows and mac have (very) flawed wifi ad-hoc implimentations. Linux’s is a little better but not by much. I guess it’s the ‘forgotten mode’ of 802.11b/g.