Redcore

This isn't a pure PHP question. There is no way a website (in any language) can connect to someone's computer like that without any sort of program the user can download/install to talk to the site. You'd have to build an API into your PHP site that the program (which could be written in C or Python - depends what you want to do and how you want to package it) can callback with the contact information it extracts.

For that contact information - that's a little tedious because of all the different types of phones and platforms out there, but there are a lot of projects you can probably use to get this stuff.