Pick Up the Pieces.
As much as I hate seeing peoples friends let them down, I like to pick up the pieces.
The best thing I have done was when a coworker of mine was getting married and neither her friends or her bridesmaids were going to throw her a bachelorette party, so I took it upon myself to throw her one at my place. Then, when not even all her bridesmaids showed up to her bridal shower, another girl we worked with and myself set up a surprise shower at work with everyone, and some mutual friends and regulars. It made me feel good to be able to give someone a boost they probably really needed.