These guys have the CF adaptor as part of their package.
I've been reading on this and thinking that, while it would be of little use for my Canon 20D (shooting RAW...the Eye-fi does only JPG and slowly, too) I do have a Canon S5-IS that it would work in without an adaptor.
As it is I think (if I understand this correctly) this device only works in WiFi hotspots and you first have to get it to connect to your wireless connection at home via the WiFi after which the card will start sending to the Eye-fi server which in turn uploads the images to an image share site of your choice. I don't know if it sends directly to your home computer though...I don't relish uploading to anywhere else than on my own drive...and as I said only if you are in a hotspot.
But the photojojo site also deals with the situations (like a wedding location shoot) when you aren't near a hotspot. Then you have to have a laptop to download the images to and a portable wireless modem/router which will then upload to your home computer. Just what I need...more technology for me to misplace, have stolen, or just outright crash on me in the midst of delivering the files.
But if anyone here on G1 has one of these cards I'd be interested in reading what they think of it...and whether it's a smart investment or 'yet another toy'.