i couldn't find the 2.48 release at all on the main blender site.  i'm probably dense, but in case you have a similar problem, here's the link to the GraphicAll site where i did find it.
http://graphicall.org/builds/index.php

and here's the link to the 7-Zip tool i needed to actually unzip it.
http://www.7-zip.org/

if anyone has suggestions or instructions on using the Shrinkwrap modifier, i'd love to hear them!