As I reported earlier, I gave up on the SonyEricsson M600i, due to the problem of sync that phone with MacOSX. For a while I have looked around, and hesitated, but it turns out the best solution right now is something unspeakable...
My choice is: HTC TyTN. Allthough that phone uses the winblows mobile 5 operating system, it seems to be the best smartphone around that both have WiFi, qwerty keyboard, and possible to sync with Mac. To sync it, I have purchased missing sync from Mark/Space, it works quite well. It was some issues with connecting TyTN and the Mac on bluetooth, but once up it is a ok combination.
Maybe I care to give a more thorough review of the features of TyTN and how it pairs up with the Mac later on, but for now I just want to say that I can sync appointments, contacts, and I can mount the phones' storage as a drive. That I can both use skype and IM clients on the phone is of course a plus :-)
Take care,