telephone
If you want to call to North America, find the "Club Plus" card. Do not be talked into any other card. They are usually found at the nightshops Nacht Winkels. You can get more than 200 minutes to North America for 5 Euros from a payphone. This is great since payphones cost quite a lot if you just insert money.
internet
In recent years, the number of Internet Cafes has grown very rapidly; it is always very easy to find one within walking distance. The going price ranges from 1.5 euro to 3 euro per hour. There is also free wifi on the Graslei near the center.