Long time ago I was working for Gammu/Gammu+ projects (backup/restore and other PcSuite functionalities). Unfortunately, because of total lack of help from Nokia/other people and developers side projects in fact were less or more suspended from some moment. I think, it could be possible to add plugins for them or even make ports working exactly on N900 (hehe, sending EMS, decoding SMS in "non-Nokia" formats and so on ). But for real development there is required earlier or later real device and I hope, that it will be available up to the end of year, maybe a little later (ehhh, availability in shops + money )...