An introductory video (youtube) by bytebodger describing the use and creation of pivot tables in Excel 2007.

Here is a video from freetutorials (youtube) on using Excel to manage simple databases.

The REPT function repeats text a given number of times. For example, =REPT(”*”,10) repeats * 10 times in a cell.
You can use this function to create a simple bar for values in multiple cells.  Here is a short video on YouTube:

Personally, I use Excel 2003 at work and Excel 2007 at home. I am constantly (as in 3 or 4 times a weeks) using Excel 2003 files in Excel 2007.
I found this tip at vista4beginners.com showing how to have Office 2007 automatically have files in the Office 2003 format: Configure Microsoft Office 2007 to save [...]