Sat phone won't work with the Neo900 alone, you definitely need a cradle that provides a battery and an antenna at least, even if you had a "GMR modem". Honestly Neo900 Thuraya phone is pretty far fetched, but at least not impossible. Motorola did similar thing, placing a rather normal GSM phone into a cradle with an antenna and quite some additional electronics. The OTA protocols are somewhat similar for GSM and GMR, and that's it. The Motorola cradle was quite above 1000$ iirc, and maybe that even been for Iridium and not Thuraya, can't recall anymore. [edit] Hmm, Thuraya sleeve phone, revival of the motorola cradle. And it has adapters for iphone4 and iphone5. An adapter for N900 isn't completely mad to figure.

For the rest of electronics in Neo900: it won't eat significanlty more power than Neo900. It's not that much different in the end.

/j