Excel: How can you restrain text from flowing into adjacent blank cells?

I use Excel to list my inventory for an online auction site. When you type in text that is longer than the width of the cell (say,cell B2), the text will spill over into the adjacent cell (B3) if it is blank. This makes it very difficult to tell at a glance if I have left cells blank that need to be filled in. I do not want to resort to “text wrap.” Is there a way to restrain the text to its own cell?