All of these sites include images of spring peepers, and many have recordings of their song.
Northern Spring Peeper
Rhode Island Vernal Pools, University of RI Dept. of Natural Resources Science.
http://www.uri.edu/cels/nrs/paton/photo_sppe.htm
Southern Spring Peeper
Florida Wildlife Extension, Dept. Of Wildlife Biology and Conservation.
Institute of Food and Agricultural Sciences at the University of Florida.
http://www.wec.ufl.edu/extension/wildlife_info/frogstoads/pseudacris_crucifer_bartramiana.php
Pseudacris crucifer
Animal Diversity Web, University of Michigan Museum of Geology.
http://animaldiversity.ummz.umich.edu/site/accounts/information/Pseudacris_crucifer.html
Spring Peeper
AmphibiaWeb, in conjunction with the Digital Library Project, U.C., Berkeley.
Search for "spring peeper" under vernacular name.
http://elib.cs.berkeley.edu/aw/search/index.html
Spring Peeper
The Center for North American Herpetology.
http://www.naherpetology.org/detail.asp?id=1130
Spring Peeper, Pseudacris crucifer
Northern Prairie Wildlife Research Center, USGS.
http://www.npwrc.usgs.gov/resource/herps/amphibid/species/speeper.htm
Spring Peeper
Wildlife Diversity Section, Indiana Department of Natural Resources.
http://www.in.gov/dnr/fishwild/endangered/spring.htm
Compiled by Allison P. Kelly, March, 2005