Google actually has a game, and it is quite addicting. You either sign in or play as a guest; you get a partner and you both get to waste time together.
You team up with a second player, you're provided with a random image and a few off-limits labels and then guess alternative labels for the random image.
This game actually does some good for Google. It's designed to improve the relevance of image search results.
Go around the world all over again. Make music like Daft Punk; work it, make it, and do it with the buttons using your keyboard or mouse. Not sure how long one could go on this site.
A website dedicated to randomness. Flip a coin, roll dice - all 100% random. Offers true random numbers to anyone on the Internet. The randomness comes from atmospheric noise, which for many purposes is better than the pseudo-random number algorithms typically used in computer programs