"stumble" instead of speaking clearly. the mistake will usually produce a smile in those listening to your attempt.
you can check out the various tongue twisters on the other pages in this section. a good place to start is with the "5 times fast" category.
if you know of a tongue twister that you would like to see listed on these pages, just type it into the chat box on the bottom of any of these pages. please make sure it is not already listed before suggesting that i add it. 