I believe you'll need a macro to accomplish this, but I wouldn't recommend
it, because sometimes you are opening other people's workbooks where the
text wrapping is already set correctly. If they have not protected their
worksheet, you'll just make a mess of it every time you try to open it.
When you open Excel, you can just turn this on right away by clicking the
box above the 1 and beside the A (this selects your whole worksheet) and go
to Format | Cells | Alignment to check the Wrap Tex box.
