Scholastic
Scholastic: Max's Math Adventures: Max's Measuring Mania
Read about how Max and Ruthie measured some fun objects in their gym. Use this method to measure things in your classroom. A helpful teacher's guide and extra challenges will make this a fun lesson on measuring with nonstandard units.
University of Cambridge
University of Cambridge: Nrich: Hand Span
Use this one page website to practice measuring things using nonstandard units of measurement. There is a solutions page that is right at the website for more information.