When trying to format as text, excel will only format the output, retaining any number VALUES thus making numeric value cells only sortable as numbers (good in some circumstances). If you want to sort as alphanumeric then use the Data->Text To Columns wizard. It will format the VALUES as text.
Drop down list for user input: Menu ->Data, Validation, then select list as type. Can directly input the possible values or select a range that contains them from the sheet (which you could then hide).
To create a filtered list - highlight a cell and go to data->filter->autofilter.
View VBA behind current worksheet: ALT+SHIFT+F11
Pivot table field list is made visible again by highlighting a cell in the pivot table - duh!
Press ALT+ENTER to start a new line while you're typing or editing data in a cell.
Paste Options button appears after pasting and gives you the option to keep or throw away source formatting.
CTRL+; to paste todays date.
F11 when highlighting a series to auto create chart. (AWESOME)
A green triangle in the upper-left corner of a cell indicates an error in the formula in the cell.
Format paintbrush tool will paint format of cell that was selected when painter button was hit onto cells that you then highlight.
!! - If you edit a chart created from a table then the table gets edited at the same time - they are not independent!!