Interesting video demo of some femto applications here, courtesy of ip.access. They use a couple of different devices (Nokia N95 and a Samsung Windows Mobile smartphone) via the femto to control either a home media server, or a SlingBox.
One of the interesting aspects is the adaptation of UPnP to work over 3G (Universal Plug'n'Play, as specified as part of the DLNA standard for home networks). Having asked about some more details, I found it interesting that getting the UPnP demo working over 3G is not currently possible on the N95, as the client software in that phone assumes it can only work over WiFi.
Now, wouldn't it be useful to have a handset OS connection manager that could tell the application about the availability of a UPnP-suitable 3G connection (ie via the femto when the user is at home)? And wouldn't it be good to get UPnP support in non-WiFi handsets?
(Of course, if the phone has both WiFi and 3G, the "policy management" of in-home networking gets a bit more complicated as well).
These are some other types of subtle "femto optimisation" approaches to mobile phones. DLNA and full-featured connection managers are both covered in the "Femtocell-Aware Handsets Report", published yesterday by Disruptive Analysis. More details & contents pages are now available here.