Create link that adds vCard direct to Address book

[UPDATED - Sep 2013 - iOS7 now supports direct download of VCARDs from we page and import into native contact application]

Complete solution using VCALENDAR file with emebedded VCARD file is published here

iPhone: how to get safari to recognize a vcard?

which includes link to my blog with full source code on the subject at

http://mobicontact.info/iphone/download-contact-from-web-page/

I hope this is of some help...