For my daughter's 6th birthday, we had a "tie-dye" party.  Everyone was given a new white T-shirt and asked to use the provided elastics to create their own pattern.  Then we each took turns adding the colors. Everyone went home with their T-shirts in a ziplock bag as the T-shirts had to sit for several hours.  The next day we got calls from everyone telling us how great their shirts came out.  It has been over a year and we still see her friends and their parents wearing their shirts from her party!