On one level, you're preaching to the converted - my servers are FreeBSD, my desktop is Debian, my router is DD-WRT and I didn't buy a Linux phone by accident. :-) That said, I can pay for one contract SIM at a time, so the N900 is most definitely a phone - in fact, it is now my only phone, being the only GSM terminal I carry and also the SIP phone that fields all my landline calls when at home.