Topic: Valuable, large site for learning more about mic positions
Many audio files and photographs, and not just for recording piano--the first link on the home page is for recording guitar. Scroll down to find the link for piano setups, with around 70 audio files illustrating the result of each. They used the small diaphragm Rode NT55's for these recordings, sometimes using the omni capsule and sometimes using the cardioid capsule. There is text describing the setup for each set of recordings:
http://www.cambridge-mt.com/rs-lmp.htm
The recently praised XY setup is the last one on the page for the grand piano. They positioned the mics at three locations to illustrate the difference in the sound in the three variants of the only close mic'ed setup. Versions B and C do it best for me. Makes me want a pair of those mics, along with more mic presets in Pianoteq.
[EDIT: I originally wrote that all of the mics used the omni capsule on these mics, but now I see that they sometimes used the omni capsule and sometimes switched to the cardioid capsule.]