A good site for http://www.afb.org/braillebug/default.asp

You can get the children to write their names in braille form.
Use black poster paper,or any colour of your choice.
Write the name in braille, press hard so mark shows through to back then using a pin or some sharp point press through the paper from the back.
This leaves the name in braille. They think this is great. If an older group you could teach a letter a week.