Where can I download older versions of Oracle Instantclient? Version 10.2 is linked from here, but I need 10.1.  Any clues where to get older copies of the instantclient packages?

http://www.oracle.com/technetwork/database/features/instant-client/index.html
Here's a link that lets you download 10.1.0.5:

http://www.oracle.com/technetwork/topics/winsoft-085727.html

This particular link is for 32-bit Windows.  Hope this helps.