I've use a simple little hack like this (follows). I know it doesn't work in older Netscape browsers, but somewhere in these last couple months I've pretty much opted to just blow that browser off, I don't use it anymore, why should other people? ;-) This following bit should work in all modern IE versions, as well as Mozilla.
------------------------
| This is my button/cell text |
| Short text |
| This is my button/cell text |
----------------------------