slightly different, but in the same flavor, when others are telling jokes. you can slip these in.

do you know the joke about the rope?
Oh, never mind, skip it.

have you heard the joke about the wall?
Forget it, its over your head anyway..

Did you hear the joke about LA? (or the city of your choice)
Its a riot!

I know a lot of blonde* jokes (*or ethic group of choice).
They are all beauts, but simple minded.