Hitting two birds with one stone

I'm aware that PCs are capable of multi-tasking which makes work of users a lot easier. It's an advantage which seems to be heaven for us. However I don't find it this way at all times. There are times that this feature of computers make me more nuts. Why? I simply can't concentrate. I lose my focus from the more important task. I'm tempted to do other stuff. Okay! okay! its me who is at the loose. I should admit to myself that I can't prove that "Hitting two birds with one stone" is possible---well ofcourse i'm referring to my case.