Perhaps someone could compile a list of funds where the managers both do and do not invest themselves and then compare the performance of the funds against each other?

I think you would have a hard time coming up a system of randomly selecting funds for that type of comparison.  Instead maybe a quick survey of the funds with the highest long-term returns and see whether or not the managers have a personal stake.  Then repeat the survey, except looking at the funds with the lowest long-term results.  Possibly even expand the survey to include funds from different categories - aggressive growth, large cap, micro cap, global, asset allocation, etc. 

The results would be quite enlightening I think.