April 30 2007 will be the Hindu festival of Narasimha Jayanthi.
Narasimha, the man-lion (nara-simha), is one of the incarnations of the Hindu god Vishnu. A demon named Hiranyakashipu, an avowed enemy of Vishnu, had acquired great powers, and could not be killed by human, deva or animal. His son, Prahlada, however, was deeply devoted to Vishnu. Hiranyakashipu was outraged and tried to kill his own son, but Prahlada was under Vishnu's protection. Defying his father, Prahlada was not afraid and maintained that Vishnu was everywhere.
Finally, Hiranyakashipu asked his son if Vishnu was in a pillar. When Prahlada affirmed that "He was, He is and He will be," Hiranyakashipu smashed the pillar, and Vishnu emerged from the pillar in the form of the Narasimha. As a divine man-lion, Vishnu was not simply god or human or animal, and hence Hiranyakashipu was not protected against him. In his ambiguous form, at the ambiguous time of twilight, in the ambiguous space of the threshold, Narasimha put the demon Hiranyakashipu on his lap (neither on the ground nor in the air), and killed him.
You can read about Vishnu's incarnation as Narasimha at wikipedia. You can also read the story at Encyclopedia Mythica.
You can read Prayers to Lord Narasimhadeva at Stephen Knapp's website. There are photos of Narasimha worship at Photo.net, and you can see a slideshow of a 2005 Narasimha Festival and a 2006 Narasimha Festival in Bangalore.
Here is a Yoga Narasimha statue at a temple in Vijayanagara, Hampi, India (wikipedia).
Here is a beautiful image from the British Library: "This page comes from an 18th-century folding cloth book of religious and mythological oil-colour paintings, copied from originals in the Brahmanical Pagoda of Chokalingam at Madhura in Karnataka."