Clothes that repel insects?
I found this news article very interesting about a clothing line by Buzz Off that repels insects. What a very tight niche. I bet that this really catches on, just like organic clothing, as people become more and more aware the side effects of the chemicals we use.
You can read more about it here:
http://news.cincypost.com/apps/pbcs.dll/article?AID=/20070705/LIFE/707050334/1005