This is partly prompted by ignorant folks on freecycle. If I say I am going to be somewhere and I have a phone number then if I cannot make it I call. It doesn't take much. An email apologising for screwing me about would be nice too.
Another rant if someone PM's asking if something they sent has arrived REPLY it won't kill you and if it hasn't arrived they will re send.
Common courtesy is a thing of the past I swear (literally I've been cussing the past half hour)