SFR in France (once part of the Voda empire) also offer Femtocells, you just have to ask. They charge 60 euros, but credit that to your mobile bill so the Femtocell is effectively free. You can order online, giving up to 5 mobile numbers, and the box is delivered within a day or two, already setup. Just plugin, and after a few minutes (in my case) the operator logo on the mobile changes from "SFR" to "SFR Femto".
The box is designed to look like the SFR broadband box, and if you have broadband servive from SFR the two just clip together. Otherwise it's a simple ethernet connection back to the router. Works with any broadband provider, but comes with a warning that if they detect it being moved to another location after initial setup they may disable it. They will disable it if it is used outside France (I haven't tried it through a tunel from elsewhere. Yet.)
I haven't tried range checks or handoffs yet. In my case I do have a decent SFR signal at home, but there is only one cell mast in range. When it goes off-air, as it does from time to time (storms, lightning, etc) I lose cell connectivity so I decided to try the Femtocell as a backup, since it's free :) So far, so good.