I usually go to the client workstation - go to the portal page - do a view source and at the bottom look for:
<!--Portal Version: 10.3.0.337003, Changelist: 337003, Build Date: 10/08/2008 at 02:57 PM-->
So here we are using 10.3.0
<!--Portal Version: 188.8.131.529005, Changelist: 329005, Build Date: 05/22/2008 at 01:51 AM-->
in <server> bea\alui\setting - configuration.xml also has versions of products.
WCI has a few xml files that can help you find the version and, more importantly, build number of your installed product.