The iplayer is downloaded from 't'internet, so you need to connect you computer to the TV, by an HDMI cable, so you can see what's on the computer screen on the TV, go to the iplayer page and sort out the iplayer download.
So all you need is an HDMI output on computer and one for the input on the TV.
Some really up to date TVs can access Iplayer directly without a computer, via network connection.
Some PVRs also have the iplayer facility built in eg..
http://www.humaxdirect.co.uk/product.asp?ProdRef=10095&cat=stb