I have a 2011 13" 128gb core i5 MacBook Air with only 4GB of ram. I feel like 4gb of RAM won't last me too long. Is it possible to upgrade the ram myself to 8gb? And also, my Air never has more than 2.7GB of ram available according to istat pro. I have every application closed with no indicator lights and I did a restart and it can get about 2.5gb of ram available. I have an application called FreeMemory from the app store and it can free up 100-200mb normally. I have 4 tabs in firefox right now, 3 tabs in safari, textwrangler, and textedit and I have almost 1 gb of ram.