Generating ideas is great. I usualy come up with one while I am working on something and I can relate it with something I thought of earlier. But ideas are nothing until executed. Most people feel that some of their ideas are great but once they find that something similat already exists, they drop it. Most of the new/upcoming businesses are simply a better way of doing the same thing, so simply refining the ideas can be the key to come up whith something which is worth a try.