Here's a list fo sites I visit for software for my Windows Mobile 5 (WM5) device:
http://www.freewareppc.com/
http://freecabs.org/
http://marcusvorwaller.com/blog/archives/2004/06/02/the-best-pocket-pc-freeware/
http://ppc-resource.blogspot.com/2007_08_01_archive.html