Twitter‘s co-founder, who’s also CEO of Square Inc, joins immediately and will stand for election at the March 18 annual meeting. He seems to be filling a Silicon Valley seat on the board: Disney notes that JLABS CEO Judith Estrin — a former Chief Technology Officer for Cisco Systems — will not be on the ballot. She joined the Disney board in 1998, and the company’s corporate governance guidelines limit directors’ tenure to 15 years. “Jack Dorsey is a talented entrepreneur who has helped create groundbreaking new businesses in the social media and commerce spaces,” Disney CEO Bob Iger says. The entertainment giant’s strategic priorities “include utilizing the latest technologies and platforms to reach more people and to enhance the relationship we have with our customers.” A fun fact for trivia fans: On March 21, 2006, Dorsey posted Twitter’s first tweet, which was, “just setting up my twttr.” He was Twitter CEO until 2008, when he became chairman. The following year he co-founded Square, which develops digital payments processes including an iPad point-of-sale system, and an application that enables consumers to use their mobile devices to pay for goods and services.