One link which was interesting and surprising to me, was The Mystery of the Threshold: Ali of Southern India by Ulrike Niklas, about eunuchs in Chennai. I had thought of hijras as being a primarily northern Indian phenomenon, but apparently they have a long tradition in the south as well. One of the alis, as they are called in Tamil, mentioned in the article, was a priestess of a temple of the goddess Angalamman.
Here are a few other links:
The Hijra Community, an article and a glossary of terms
Livick Archives -- some remarkable portraits
Hijra: the Third Gender in India -- from Takeshi Ishikawa: The Works on Hijra, with portraits
Photo Essay by Anita Khemka - MUNNA GURU-Portrait of a Eunuch
Fashion: Eunuchs dazzling on Indian catwalks
The Eunuchs of Pakistan by Dennis Drenner - with a photo essay
Feminine Soul, Masculine Body from the World Press Review (hijras in Pakistan)