Collaboration Not Competition
Customise ISA login page - http://technet.microsoft.com/en-us/library/bb794733(TechNet.10).aspx
Customise MOSS alerts - http://blogs.msdn.com/sharepointdeveloperdocs/archive/2007/12/07/customizing-alert-notifications-and-alert-templates-in-windows-sharepoint-services-3-0.aspx
Add CSS to InfoPath - http://www.infopathdev.com/blogs/greg/archive/2005/06/07/Add-a-Custom-Style-Sheet-to-a-View.aspx