Using no apps or anything on Mountain Lion on my 2011 MacBook Pro with 8 GBs of RAM, Memory Clean (and Activity Monitor) say I have around 4-4.6 GBs of RAM available. For doing nothing. I regularly go down to almost 0 MBs available by running just 1 Virtual Machine in Parallels Desktop 8 with 2 GBs of RAM allocated to Windows 8, running Safari with Flashblock installed and a couple tabs, iTunes, and Microsoft Office. Does this sound right? I never had any problems with RAM in Snow Leopard. In fact, under the same usage noted above (With Parallels 7 and Safari 5, however), I usually had 2-3 GBs of RAM available VS. none.