Do you own the Classifying Cards from Super Duper? (http://www.superduperinc.com/products/view.aspx?stid=353#.UwP87vldXVE)
I do! Among other things, I use them to get some baseline data on basic picture naming skills for IEP data for my prek students.
If you use these cards for vocabulary, you will love this data sheet! I use the cards for baseline data, and do a recheck at the end of each quarter, as well. Use this data sheet to track your students' picture naming skills throughout the year!