Although I've almost never put photos on sites before I was aware that it was important to name them accurately, since this could bring in some traffic. Surprisingly, it's started to work already. I haven't had tons of hits, but there's a regular trickle of visitors to the blog coming via Google image searches. So, it looks like there's a good source of easily gained traffic there for webmasters to tap in to. The trick seems to be in naming your images correctly.
My photos are all specific and unique to Perth. So it's not unreasonable to assume that the traffic is mostly geo-targeted as well. I haven't looked into this but logic dictates that if people know the buildings and streets I've named, then they're probably also from Perth, or some other city in Australia. After all, people from overseas wouldn't have such specific knowledge of this city.
I suspect that if a local landmark is very well known, then there'll be a higher proportion of people from overseas searching for it. The inverse would be true too. So, the less well known the landmark or location you're photographing, the more localized the search engine traffic that image can bring. (Of course there'd be smaller volume, too. But if you have several photos up the effect will certainly accumulate over time.)
This is worth knowing for anyone who wants to get geo-targeted traffic. Digital cameras are not pricey, and It doesn't take long to go out and take some photos and upload them onto your site or blog.
There is a risk with using lots of photos, however, particularly ones of famous landmarks. That is that they'll get ripped off and used on other sites. So here's an article about how to address this problem.