"I'd love to hear more, however I don't have the time at the moment as I have a rather pressing commitment that I must attend to."
Excellent reply, and in addition, sometimes it helps to just start walking towards the door! Seriously. They'll follow you, and you can get them out of the house this way. Another thing that sometimes works is to treat the present moment in the past tense, "It was good talking to you," (not that you got the chance); makes it sound like it's over.
Thanks for your suggestions, I may try this bum's rush m1469
Make sure you do the technique properly though. First, grab the 'rushee' by the scruff of the neck with your left hand and the seat of the pants with your right hand. Next, lift up with your right hand slightly and move the 'rushee' towards the door keeping him/her off balance as you move forward.You can open the door first or not, depending how annoyed you are with them.Once outside, give one final toss with both hands, hopefully sending the person for a tumble or two.That's a proper 'bums rush'. Hope that helps! Cheersallthumbs