I'd like to be able to transfer files on my Sony Ericsson K610i phone when I connect it to my GNU/Linux system (Debian in my case) with the standard USB/charger cable shipped with the phone.
There are other methods, like over Bluetooth or IR, but my Desktop PC has no bluetooth or IR interface by default.
On OpenOBEX site there's a wiki which documents the status of various phones. For the Sony Ericsson K610i the informations are here.
I had to check many sources of information to be able to setup something useable, in addition to this link, which I try to summarize here.