I love balloons. They are so inexpensive and there are so many fun ways to use them. This fun birthday tradition from Increasingly Domestic is a perfect example. The number of balloons you get is equal to how old you are and each balloon holds a dollar.
I think this would be a fun way to give Mother's Day cards this year too! Sort of like these love note balloons.
But you don't need the helium and Mom will have to pop the balloons, which will be fun for the kids.