I tend to be a bit of a sceptic. I'll happily do my best to punch holes in any business ideas . The biggest problem with this is that if its a genuine half decent idea, guys are going to try and keep it out of the public domain for as long as possible - until it comes to sales time.

I've had extra capacity in terms of staff, factory space and other basic infrastructure for years now, but have still not managed to find products to take up this slack. It of course doesn't help that I tend to need serious convincing when it comes to business ideas. I am of the view that a decent new product needs somebody to "champion" it and get the first sales going by using their specific skills, experience and/or contacts. Finding someone to do this is tough.

However it will be interesting to see if what people might add to your list.