I use fan sites mostly when it comes to celebs (they have the best pics and everything in one place), fashion blogs and fashion blog hubs like lookbook for non-celebs. Google Images and assorted forums/databases (superiorpics, bellazon, theplace2.ru) are also great. A lot of my searches originate from people I see at http://cp.reddit.com/r/WomenWithWatches and this place, making me want to search for more pics of them. Auto/gaming shows with grid girls and booth babes also have several watchgirls. Flickr has several albums/groups for those.