My age has been incremented by one on this birthday, but sorry; I'm not yet ripe to get married.
Does the above line seems like a story? Well, to me its not ;)
Stories in one line is gaining popularity now a days. This is the link to the longest one line story I have read till date.
http://www.netscrap.com/netscrap_detail.cfm?scrap_id=508
Stories in exact 50 words is called mini-saga. Here is a guide helping you how to write one.
http://www.learnenglish.org.uk/magazine/magazine_mini_sagas.html
A few good ones in malayalam can be read here. Try writing one, its not as easy as it sounds.
http://palavaka.blogspot.com/2006/06/50.html