"Yes, Duncan. I've invented a picnic rug which, at the touch of a button, can be turned into a horse."
Next . . .
"Thank you, Duncan. I need a million pounds to market a special tape which can tell whether the peanuts on a pub bar have too much urine on them."
Next . . .
Things are even more mad if you delve into the Patents Office to see what the world's inventors are up to these days.
It seems one bloke has invented a pair of trousers which can be turned into a seat. And another, called Brian, has developed an orbiting satellite which can rain nuclear bombs on Beijing.
He doesn't explain who might want to buy such a thing. Or what Beijing has done to deserve such a fate.
But by far and away the stupidest idea for making money in the whole of human history is not in the Patents Office or on Dragon's Den. It's on the interweb and it's called Skype.
I would dearly have loved to have been in the bank manager's office when the inventors strolled in and asked for a loan to get their idea off the ground.
"Yes. Our idea is that you download a programme from the internet, which costs customers nothing, and then they can make completely free video phone calls to anywhere in the entire world. How brilliant is that?!!!".
Right. So it doesn't cost anything to buy. And the calls cost nothing either.
I bet the bank manager exploded from laughing so much.
But I bet he's not laughing now because Skype was sold to eBay in 2005, netting the inventors £5.2million. I still don't understand how it makes money but I do know it's brilliant.
I have it on my computer now - under a false name - and sometimes, just for the hell of it, I ring up people in Milwaukee just to laugh at them for living in Milwaukee.
And here's the really good bit. You can have a conference call. This means you could have a dinner party, for all your closest friends. And not bother cooking anything. Or even inviting them.
The only drawback is the video bit. The idea that you can see the person you're talking to.
This worked fine on Thunderbirds but when you are being watched, it is very difficult to lie. On a normal phone, it's very easy to say you are working hard. You only need to get your voice right. But when you have to get your face right as well, that's tricky.
Especially when the caller can see that, actually, you are butt naked on a table, in the middle of a Vietnamese sandwich.
I suppose the only good thing about video calling is phone sex.
So far, though, everyone I've called has been a man or a moose.
Despite this, there's no getting away from the fact that the calls, Skype to Skype at least, cost nothing.
And that's just epic.
I can only hope now that the inventors, with all their cash, buy Ferrari and design a car which costs nothing to buy.
And nothing to run as well.