The cool part: virtualapple.com lets you relive your childhood by playing all of your favorite Apple II, IIe, and IIgs games via a web browser. For me, this means playing Oregon Trail (which was something we did in school in 4th or 5th grade, if I remember correctly).
The really uncool part: It’s all ActiveX-based, so it’ll only work in Internet Explorer on a Windows box. (Why not do this in Java?).