When you want to fill a column in Excel with a given formula or value, you can do it the old fashioned way (select cells or the column header, CTRL+V to paste). A quicker mouse-based alternativedouble-clicking on the bottom-right corner of the cell you want to copy.
This pastes that cell's value the rest of the cells in the column, until the highest row number in the worksheet. (For example, if column A is the longest with 52 rows and you're copying the first cell in column B, rows 2 to 52 in that column will be filled with the cell value.)
You can also drag that box in the lower right corner to copy the cell down the column, but double-clicking is quicker and simpler.
This tip comes via HowTo Geek, in a post highlighting neat functions for changing the case in cells.