Hi Fishman,
If you're looking to Find and research particular Niche interests, including groups of people with like minded passions...
Try the following method...
Find The Most Popular Blogs in Your Field...
http://www.sowpub.com/forum/showthread.php?p=24345
Here's a Quick mix of misc. keyword phrases related to "investors" for realestate that might just give you a few ideas to play around with...
realestate investors,real estate investors,real estate investors club,real estate investors network, real estate investors clubs,real estate investors club utah,real estate investors club los angeles,real estate investors club nj,real estate investors club of utah county,real estate investors club illinois etc. etc...
http://tools.seobook.com/keyword-tools/seobook/
Cool and Simple ways to Do your research on Google...
http://www.google.com/support/websea...&answer=134479
http://www.googleguide.com/
Phil