This free tool has just been submitted to the Directory of Learning Tools:
GQueues lets you create,
prioritize and manage lists using your Google account.
"All list items are housed in super durable, wafer-thin containers so you can drag 'n drop them all day without any sign of wear or tear. And if you are one of those people that likes to make lists of lists, GQueues even allows you to categorize your queues for ultimate organizational pleasure."