Bluetooth for internet?

Hi i was just wondering if i could use the internet from my pc on my cell phone so that i dont use the data costs, o and i also saw a popport adapter so that i can use a 3.5mm headphones, but it doesnt say 6620, could it wokr with a 6620, has anyone tried it either?http://cgi.ebay.ca/Headset-Adapter-pop-port-for-Nokia-6610-7250-3-5mm_W0QQitemZ5819991767QQcategoryZ20371QQssPageNameZWDVWQQrdZ1QQcmdZViewItem