I was dragging my feet, complaining as I documented a COM component. With Rick's web service, you can upload a COM DLL, OCX or TLB and it will return a CHM (plus all of the source HTML file) with all of the classes, methods, properties and parameters documented. It will also document a webservice. This is an overlooked, but extremely useful tool.

http://www.west-wind.com/wwHelp/wwHelpClassGenerator.wst