Just today I 'discovered' -- by sheer accident, a feature that I had not read about anywhere on the web: When attempting to "Share Screen" with my ML-installed macbook pro to a ML-installed iMac, I got a choice -- whether to share the same screen, or log-in as a different user! I tried logging in as a different user -- and sure enough -- I was logged in and fiddling with folders and stuff while my colleague was going about her stuff on the same iMac -- but we were using completely different desktops/accounts. Is this a new feature, and if so ... what's it called? I've never seen it in Lion. What are the requirements of this feature, as I couldn't get the same options on my ML-installed mac mini. Perhaps a minimum of two user accounts needed?