What is a good interactive toy for my cat to play with when I'm not home?

I am worried that my adult indoor cat isn't getting enough exercise - what is a fun, interactive toy that will keep her entertained? When I am home, she plays with her wand toy, but seems to be growing bored of her catnip cigar. Any suggestions?|||videotape yourself and have your cat watch you playing with him while you are gone. it works.