When displaying a form, you often want the user to make a choice amongst a list of possibilities. In HTML, a choice is represented by a select tag. You can add a multiple attribute to make it accept several choices. [...] To unify all these possibilities, symfony 1.2 comes with a new widget called sfWidgetFormChoice. sfWidgetFormChoice is an abstract widget in the sense that it delegates the rendering to another widget (the renderer widget).

He includes examples of how to use the widget to make dropdowns, radio buttons, check boxes and even integrate some Javascript for handling multiple lists and autocompletes.