After some years I finally decided to buy a new mobile phone. Sorry no Linux here, Android based phone were still far out of my planned budget. My choice has so fell on the Nokia 5800 XM simply because it had all the features I was asking for (GPS, MP3 player, WIFI connectivity … and doing phone calls too, of course) at the lowest price.
The new phone has replaced my old (Nokia 3650) phone, the (even older) HandSpring Visor and my (cheap) MP3 player. Maybe I've been out of the mobile market too many years but I'm really satisfied of these first day of use: the touch-screen feedback is really good, the MP3 player sounds great and I had no problems at all in transferring files from Linux computers both using USB cable or Bluetooth. Of the many thing one I found really useful was the little utility that transferred all phone-book, agenda and messages from the old Nokia phone to the new one literally saving me from doing this manually. Curiously this feature wasn't mentioned in any of the many review I did read before buying the phone. Let me say that sometimes real improvement might not be cool but it's useful.
I hope I'll post soon about interfacing the Nokia 5800 with Linux or about programming it.