Yes you can make calls through it using skype or gizmo (VOIP). You can use a bluetooth headset. But you would need an internent connection.
There are many shops selling them online, and there are listings on ebay. It ranges in price between $450 to $550. I bough mine through nokia directly on their web site.
If that is pricey, and you don't want gps or the keyboard, but want all the other features, you can get the n800. It is roughly just over half the price of the n800
