Interestingly, sparklines (discussed in an earlier post) will be a new feature in Excel 2010. This will presumably significantly increase their popularity and use – good stuff!
Sparklines in Excel 2010!
Personal Thoughts on Creativity, Research and Other Matters
Steps & Leaps 
For sparklines that work with older Excel version (Excel 2000, XP, 2003 and 2007) have a look on MicroCharts.
http://www.bonavistasystems.com
Andreas