Right now you can get Alvin And The Chipmunks: Chipwrecked on Amazon Instant Video for only $1.99! You have 30 days to watch the movie after you purchase it, so if you are looking for a Friday or Saturday night movie for the kids you could rent it today and watch it this weekend. You also have 24 hours to finish the movie once you start it.
NOTE: The prices on Amazon can vary from one minute to the next. I can make no guarantees that the price will be the same as the one above when you click on the Amazon link. Let me know in the comments section below if the price changes and I will get the post updated as soon as possible.