There has been so much Excel and Office related info come over my desk the last couple of weeks I don't have time to do it all justice, but I will try and share it with you in an organised way as possible.
Create conditional drop-down lists. In Excel 2007 (and earlier), it’s possible to create a drop-down list. By using the INDIRECT function, you can then create additional drop-down lists that are conditional to the first drop-down list.
From J-Walk, run some code that runs 1 million random numbers and see how fast your computer is compared with others.