Already well-known for its short character length limits, in a press conference scheduled for later today, Twitter will announce that it will severely shorten its allowable “tweets”.

“I’m frankly amazed at all the crap people fit into their tweets,” said Jack Dorsey, Twitters’ founder, by phone with me yesterday. “By shortening tweets to 20 characters, they’ll be able to put their bit.ly link, and still have about seven characters left over for a snappy headline.”

Prior to this decision, “twitterers” could put in up to 140 characters, allowing Twitter tripe such as, “Recall the Tiger Woods apology... Is it me, or did it look like he was having oral sex during the press conference?” Asked whether shortening tweets by two-seventh can hamper speech on Twitter, Dorsey quickly replied, “You can say the same thing with: ‘Tiger got oral on TV’.”

Twitter rights groups have promised a fight, with its spokesperson Doug Degas tweeting the following announcement to his 31,794 followers: “#Sign #our #petition #to #keep #us #blithering #on #twitter http://bit.ly/c1PsXn @mrsaki @sextmessage #dontyouhatewhen (This is an RT must!)”