I began by using Google to search for a few long tail
keyword phrases. Into search number three and I find
one of the major competitors site. I look more closely
at the "partners" area and there right in front of me is
their list of keywords, preformatted emails, example
adwords adverts, together with a list of forums, a list
of related authority sites and popular blogs!
Moral of the story..
If you want to get into a niche.. look for JV, partner and
affiliate pages on your competitor sites
If you are a leader in a specific niche market, be careful
who gets access to your research information!