Oh, this could be fun. It would be even better if we could record some of them (on http://vocaroo.com/ or another website) and then post them here. I would love to give it a try, but I can't read Chinese.
Tongue twisters.
红凤凰,粉凤凰,红粉凤凰花凤凰。
It will drive non-native speakers crazy. ;)