[jcstauffer]

When my son was a toddler, he referred to all heavy equipment (bulldozers, etc.) as "Err-err"'s - referring to the primary sound they make.

One of my fondest memories of this time was him walking backwards down the hall making the "err err" sound of a bulldozer backing up...

[yetihehe]

  Father and son stand in queue behind obese man. Son says:
  - Wow, what a big man!
  - Shh, don't say that loudly.
  Then man's cell phone got sms, son says:
  - Run, he's backing up!