I use a Buffalo Linkstation II 250GB (MIPS variant) running modified firmware to allow root access and a media server to be installed.
Modified firmware is Openlink 0.52b from http://www.linkstationwiki.org
Media server is Twonkymedia from http://www.twonkyvision.com
This is connected via wi-fi to my Soundbridge, using a Netgear834G wireless router.
I was very impressed with how this setup all worked together first time. The Soundbridge found my wireless network, I entered the WEP password, and it recognised the Linkstation media server automatically.
Browsing media files using the standard Soundbridge menus is somewhat slow (I'm serving ~50GB of music files). Browsing Server Containers (ie letting the server do the searching) is significantly faster, however the '+' key on the Soundbridge doesn't work in this configuration
I have noticed a few times in the past few days that the Soundbridge decides to lose my wireless network (while my laptop is still happy with it). I end up needing to do a couple of resets and re-enter the WEP password a few times (very painful) before it will re-connect. I don't think this is anything to do with the Linkstation or Netgear router - seems to be a Soundbridge issue. Other than that it's all good