Check out this riff on the index card idea. Small notebook, then you just flip to a new page for your documentation shots. Nice, thanks Trish!
Wikipedia Loves Art is a scavenger hunt and free content photography contest coordinated by the Brooklyn Museum with Carnegie Museum of Art, The Film Society of Lincoln Center, Honolulu Academy of Arts, Houston Museum of Natural Science, The Hunter Museum of American Art, Indianapolis Museum of Art, The Jewish Museum, Los Angeles County Museum of Art, The Metropolitan Museum of Art, Museum of Modern Art, New-York Historical Society, Smithsonian American Art Museum, Taft Museum of Art, V&A aimed at illustrating Wikipedia articles. The event is planned to run for the whole month of February 2009, and the name is a play off of Valentine's Day. Although there are planned events at each location, you can go on your own at any time during the month.