I just got a new mobile phone, after I sweared that I will never touch a PDA phone again as their screens will eventually screw up. I got a Sony Ericsson W810i for just EUR 125 - it was a catch! This mobile phone is termed as the 'Walkman' phone - it makes playing music easier with respect to other phones and the battery life is simply amazing.
To my surprise it was very easy to connect it to my Linux box and transfer files. I just connected the W810i to my PC through a USB cable and my operating system will just see it as a mass USB storage device :) In my case, using Debian GNU/Linux, the phone memory can be accessed through /dev/sda1 and the memory stick pro duo is accessed through /dev/sdb1.