Today is 20th anniversary of first partially free elections in soviet block. Twenty years ago Poles choose to change their government what was possible thanks to the Solidarity movement - first free trade union in soviet block. A change that happened allowed other central and eastern European states to become free too. Few months after Poland was free Germans razed Berlin Wall, Czechs and Slovaks organized velvet revolution and other countries followed too.
A change that happened might be described in Civ4 categories as:
Government civic: from Police State to Universal Suffrage
Legal civic: from Nationhood to Free Speech
Labor civic: from Emancipation to Emancipation (unfortunatelly) ;)
Economy civic: from State Property to Free Market
Religion civic: from (lacks in Civ4: state atheism) to Organized Religion

Of course this civ-like description is just a joke, but a change that happened is worth mentioning even in a civ portal. It let us to improve rapidly our economy and instead of queuing up to a shop to get some meat we can relax at our home, playing Civ4 :)