If you haven’t seen it, Alan Renouf has made a great script called “Who created that VM?” that populates custom variables to tell you who created a VM and when they did it.
I was showing this to a user the other day and they noticed they could also use this to figure out how many VMs they’re creating a month and help track their growth rate that way. Sure enough, once you’ve run Alan’s script it’s really easy to get just such a report.
Here’s a sample of the script in action against my vCenter.
You can also export this stuff to a spreadsheet, just follow the sample code above.