Right-click the Excel 2003 cell containing the text and select "Format Cells." Click the "Alignment" tab in the Format Cells window. Click the box next to "Wrap Text" to place a check-mark in it.

Next, just under Text control, click on the Wrap text box and the words in the cell will wrap. Now for the shortcut: Enter the first line of text you want to appear in the cell and then press ...