You can gain a lot of backlinks to your website(s) if you're a keen photographer and have lots of photos to show. I've got a flickr pro account, and I put my website url under the comment field on each photograph (flickr allow html tags in descriptions and comments fields). You can link to different websites under different pictures. This of course would potentially generate good traffic if the website is related to the photograph. Try it for yourself. You can view my examples here. If you click any photo to make it bigger, the url becomes live and clickable. Hope this helps.
Interesting, it's just a shame because i host my photos on my own website. I can't be bothered with flickr even though i know the size of the community is certain to drive some traffic. My photography site is http://www.urbx.info by the way.
Now that is a great idea. Go for a walk and shoot 100 pictures of everything that moves (or don't) and then post it with backlinks. Brilliant idea!
You can also leave your URL when you comment on someone elses photos. Don't abuse it though, don't put more than one single link in a comment or under your own photos. Because flickr is a global site, your URL will get great exposure.
the problem with this approach is that the traffic isn't very targeted, it's typically just people who want to look at any kind of a pic. if you host pics on your own website, and give the pics keyword-relevant names, along with other seo, you can rank in the image search engines for terms that people are looking for. random traffic for pics has its place, tho... perhaps if you have a site about cameras?
i do it with any photo sharing sites as well as adding a watermark link in any picture. but as said before, traffic is mostly untargeted.
moreover, Flickr is actually banned in China ! you can see the pages but not the pictures. you can circumvent the issue with some fast transparent proxies in china. anything else is too slow to deal with big images.
That kind of depends though, if you have a section on your site relevant to what the pic is about (weather for example), then you can link to that section under your photograph. Hosting your own photos also has bandwidth implications that you don't need to worry about if you're using flickr. It depends on what you want to achieve I guess.
I'm now starting to see good results from this approach. I have links to my photographic site in my sig here, plus in my sigs on my own forum (6,500 posts). The photographic site is linked from all my flickr photos and a reciprocal link back is in place.