I'm interested in that as well, I know in one of the other buildings they used lucent cards, 11 meg a sec, and said they worked very well.
The cards themselves might have been sub 100 each but the hubs were like 1000 dollars from what I'm told. The used 2 hubs on a huge 3 floor office and put them both in the middle floor but they said for smaller applications the cards will just communicate themselves without the need of the hubs.