Best way is to put the micro sd card from your desire into the n900, export all contacts (as explained above) and choose the memory card as a save location. Then put the sd card back in your desire and import from the sd card within the contacts settings. vcard2.1 worked for me, when importing you get 3 options that arn't very clear, import 1, import selected or all, its the 3rd option or 3rd one down. Thats it