Those SD cards with built-in WLAN are really fascinating. Unfortunately, they work completely automatically. You can make a basic set up, but after you put the card into your camera, it works alone: consuming energy during uselessly seaching for hotspots, sending every photo (also dark or blured ones)...
But perhaps it is possible to contact the developers of eye.fi and convince them to implement a kind of API for some basic functions, for example "get a list of available WLANs" and "send picture X to WLAN Y". And the CHDK developers could implement a menu entry where the user can select the WLAN and the picture to be sent. That means, the user could get full manual control over his eye.fi via the CHDK!
I think, this cooperation would be a great chance for eye.fi because their product would get a user interface direct in the camera. And therefore perhaps some money could flow from them to the CHDK developers.
Paul Lenz