With a PC running XP SP3 with Outlook 2007 and Excel 2007:
When they email a spreadsheet directly from excel, the recipients receive the email with the attachment missing the extension (.xlsx or .xls). When they try to open the email, they are prompted with the "open with program" screen.
Freeze panes is an option within all variants of Excel to enable parts of a sheet to remain stationary when the cursor is in another part of the sheet. This is a very useful feature which is overlooked or under used.
This Micro Tutorial will demonstrate how to create pivot charts out of a data set. I also added a drop-down menu which allows to choose from different categories in the data set and the chart will automatically update.