I am thinking of getting Tiscali TV as our aeriel has broken and the landlord doesn't seem to be in a hurry to fix it (2 months have already passed). If I buy an extra homechoice box from a friend of a friend, will I be able to pick-up Tiscali TV in another room (with a phoneline)??

No is the short answer. You can only run x1 STB per phone line. To get another service working, you'll need a new idependant line (with it's own number) and also set up another account with tiscali.

FYI - the STBs are still the property of Tiscali and they charge £115 for those that haven't been returned so I'd advise your friend to send it back to avoid any debt collection letters....

As the person above says, you can't do that unfortunately. There is an alternative though. You can buy an AV sender which will send the signal to another TV in the house. You can buy them for around £30+ and they fit into the scart socket on the back of the box or to the back of the television.

Not all digital senders are supported and compatible with the encryption used - you may experience FOG if you use an incompatible model (the picture may be discoloured or have lines across it).