Here’s a really simple and straightforward way to transfer contacts from almost any Sony Ericsson mobile phone (non-Android of course) to your HTC Desire:

  1. Download and install MyPhoneExplorer (free)
  2. Connect up your Sony Ericsson phone with the USB cable
  3. Extract your contacts to a single VCard file
  4. Go to GMail and login to the account you use with your Desire
  5. Go to Contacts
  6. In the top-right corner select Import
  7. Select the VCard file that was created by MyPhoneExplorer
  8. Once the import is complete you can organise them into any group(s) that you want
  9. On your Desire go to Settings > Accounts and Sync, select your Gmail Account and Sync Contacts
  10. Voila!

All your contacts should now appear on your HTC Desire!

Thanks to JoYork on HUKD for the original guide