Recently a web-designer friend of mine went to visit a guy about making a website for him. This chap's grand idea was for a website where, for just £20 a month, he'd host people's family photo albums online. Apparently the guy was more than a little crestfallen after being shown Flickr, and then Facebook, and having his whole idea destroyed in the space of about five minutes.
This also reminded me of when I went to see the RZA do a Q+A in Manchester and he announced his grand plan to release 'a new type of CD, but with video'. No-one challenged him about this.
Heard any 'great' ideas recently?