I use rooted Xperia X10 mini (model E10i) with Android 2.1-update1. Unfortunately I couldn't find any software for direct synchronization that runs on Linux so at least I wrote small script to backup my contacts.
#!/bin/sh su - << EOF cp /data/data/com.android.providers.contacts/databases/contacts2.db /sdcard/ EOF
After executing script on the phone (for example using Root Explorer or Terminal Emulator) I can copy it from SD card and open with sqliteman. It can be installed using command:
sudo apt-get install sqliteman
Now as you see on picture below it is quite simple to view contacts stored on the phone.