I am seeing sales on the Roku device as we approach the holidays. What exactly can I do with this thing right out of the box? Is there a monthly service fee or just fees for channels you buy ala carte? Is there a decent ammount of free stuff available immediately?

I tried to hook up a computer to a HDTV several times and failed miserably. Wondering if this device will get me some the results I was hoping for with a PC to HDTV hookup. Stream videos from computers on the network to the HDTV via Roku?