Straight off, no the Sony Ericsson W810i will not play .ogg music files. If it was a symbian phone then it would be possible with a quick download of an application. So woe was I when I began the process of converting my music library to mp3 format. I know, feel dirty for doing it, but it was a necessary evil.
With that out of the way, which is not the phones fault, all else is going brilliant! As soon as I connected the phone to my laptop Ubuntu detected it straight away. On your desktop, or media folder, you will get two new icons. 'Phone' (for the internal memory of the phone) and 'Phone Card' (for your SD card). As default 'Rhythmbox Music Box' will open to handle the files. Using this you can just drag and drop your music onto the SD card. Though the annoying thing here is that the titles will always come up 'short' on the walkman. For instance, instead of 'The Killers' I get 'The Kill' and so on. This effects all titles. The songs play perfectly though so no issues with sound quality.
What about bluetooth? First make sure you have downloaded 'Bluetooth File Sharing' & 'Bluetooth Analyzer' applications from Synaptic. Once installed setting them up is very straight forward. Then to send a file to the phone (with bluetooth turned on) just 'right-click' a file, select 'sent to' and then choose 'Bluetooth' from the drop-down menu. The phone will then ask you if you want to select the file. Simple. With a few terminal commands you can even use the phone as a remote mouse and media player (link below).
Next, syncing my Evolution Calendar and Contacts with the W810i. This can only really be done with 'multisync'. Others like 'wammu' are better for mobile phone utilities, but 'multisync' will sync with Evoultion. This is not as easy as the software you would get with a Nokia for win-doh's, but I imagine it will continue to improve with time and it seems to do the job with some tweaking. Again, set up is straight forward. Just go through all the tabs and drop-down menus in multisync to set up your connection. Choose what you want to sync and away you go.
I found some very good links to help out:
W810i & Amarok Music Player
Bluetooth Sync with Evolution & W810i
Bluetooth Remote Control
For some cool themes, ringtones and so on:
Personally, I am very impressed with this little phone and have no complaints with any of it's features. I would just like to see more support from the mobile phone manufacturers, none of the PC software that comes with the phone will run on Ubuntu (even with WINE) and the same goes for the downloadable software from Sony Ericsson. This really lets down what could almost be a perfect little package.
Ubuntu, Linux for human beings!