said 10 months, 4 weeks ago:
@lynnefellows I typically just subscribe to a lot of blogs in the niche I want to write about and see what kind of topics they are covering. That way you can see what is popular among people in that industry.
Google Alerts is a good alerts system if you just want to receive daily updates whenever a specific keyword or keyword phrase comes up in search results. If you just put in photography though, prepared to get a LOT of results. :)