Johanka
Use keyword tools and do your research (go to digitalpoint, nichebot, nichewatch) then you can put in the keyword into say google and find out how many competing sites they are.See how popular they are (page rank) and see how many sites link to it (read up on analysing a web page using SEO techniques) Take a look at the sites and do what they aren't doing. There is still a lot of opportunity out there. Don't forget that a lot of people using the internet are from out side the US and that is still a large unexplored area.
You have people just blogging about lindsay Lohan, Paris Hilton, HP 3750 (ink jet printer) and they are making enough to pay their bills every month. And no you don't need a grant/institution behind you. The research can be done in one afternoon/evening.
