Second Life is a wonderful place to take pictures. The creativity of builders, animators, and residents means there is always somewhere new and amazing. (And if you want pointers to such places, they are easily available. Look at Second Life residents' flickr or Picasa galleries, and at blogs that feature such photos. Dorka Barzane's Caminante de Sueños is a great place to start.)
Once you've found a place, Second Life gives you an advantage over RL: you control the skies. Create your own Windlight settings or find some created by others that you can use. Some Second Life clients come preloaded with a batch of them.
I have 453 pictures up on flickr as I type--I've taken more, but I don't put everything on flickr. Some aren't up to snuff, or are experiments with slightly different point of view or pose or whatever, so there's no point.
I'm not a great photographer. I'm no Maggie Bluxome or Whisky Monday... but once in a while, I happen upon a combination of location, lighting, and, if it's not a landscape, pose and clothing, that works. It happened this morning, I'm happy to say. The results are above.
It's a good time to take pictures in Second Life, and I hope that the mapping happens soon so it will be even better. (And could we bring back global illumination, please? *bats eyelashes*) The depth of field means that you can use still more techniques that photon wranglers :)--er, real life photographers--use, like bokeh or intentional shallow depth of field to keep the emphasis on a subject. There are tutorials, and many of the principles, e.g. composition and lighting, are the same in SL and RL... so if you haven't dared before, give it a try.