Okay so there really is no time machine to my knowledge, but that doesn't mean you can't get your hands on the AU handouts from past years. However, until that day happens when we can step back in time, you can revisit your favorite AU classes that you might have missed or lost the handouts for by downloading the handouts from the AUGI website. On the AUGI website you can get your hands on the AU handouts from 2000 up through 2005, nope sorry no 2006 this year. The handouts can be located on the Autodesk University Course Handouts page on the AUGI website.
Note: You will need to be a member of AUGI to access the website and the handouts, but membership is free though.
UPDATE (3/27/07): I was just recently tagged by Joseph at Autodesk that I forgot to mention that the handouts from AU 2006 are avilable on the Autodesk Univeristy website for download. If you attended AU 2006, feel free to download the handouts to the classes that you missed or look them up on the CD that you should have received last year.