Yankel, Minnie's young son comes rushing in from school one day,  all out of  breath, shvitzing, gasping for air. "What's wrong!?" cried Minnie.

"Oh, Mamma, you'll be so proud of me! Today, I saved the whole two
dollar fare by running behind the bus all the way home."  

"Oy!" Mamma replies, "You couldn't have run behind a taxi and saved $20?"

—Forwarded by Rabbi Baruch Lederman, Congregation Kehillas Torah, San Diego