Data analysis and visualization for Excel, for free
XL Toolbox is a free Excel statistics addin that helps analyzing and presenting data: Smart custom error bars, chart design, chart export to TIFF; formula builder, transpose wizard, analysis of variance (ANOVA); automatic backups, workbook management and more.
MyDataBars is a Microsoft Excel add-in program that draws data bars in worksheet cells. This program will enable you to create data bars in Excel prior to 2007.