These are the ideas I've found today that I'm adding to my ideas file. They could both be used as last minute Mother's Day gifts (Grandmother's would love them too). There are lots of other great ideas on the rest of their blogs, so spend some time checking them out.

Simple Aprons:
http://crapivemade.blogspot.com/2009/05/apron-in-hour.html
Edit: My friend, Dr.T, made one using this tutorial. It turned out really cute, see it here.

Painted Glasses:
(Could be done on one of those Sweet Tea/Lemonade Jars too. What is the real name of those things?)
http://whimsy-girl.blogspot.com/2009/05/last-minute-moms-day-gift.html