I generally keep none open while it's in my pocket, and then while using it it goes up to three or so, mostly having to look something up, based on the real world, (eg, sister asks me what I think of a restraunt, I pull it up in MicroB), but I can easily snap back to whichever one I was using after I'm done looking at it. Occasionally I'm loading quick applications while I wait for others (eg, openoffice) to load, (yes, I'm really impatient) or copying information from one application to another (eg, terminal commands.)