From the groaners listserv. The second tale is ancient; older than the category of blonde jokes.

A couple of blond men in a pickup truck drove into a lumberyard. One of them walked in the office and said, “We need some four-by-twos.”

The clerk said, “You mean two-by-fours, don’t you?”

The man said, “I’ll go check,” and went back to the truck.

He returned a minute later and said, “Yeah, I meant two-by-fours.”

“Alright. How long do you need them?”

The customer paused for a minute and said, “I’d better go check.”

After awhile, the customer returned to the office and said, “A long time. We’re gonna build a house.”

Two blondes were working on a house.

The one who was nailing down siding would reach into his nail pouch, pull out a nail and either toss it over his shoulder or nail it in.

The other blonde, figuring this was worth looking into, asked, “Why are you throwing those nails away?”

The first blonde explained, “If I pull a nail out of my pouch and it’s pointed toward me, I throw it away ’cause it’s defective. If it’s pointed toward the house, then I nail it in!”

The second blonde got completely upset and yelled, “You moron! The nails pointed toward you aren’t defective! They’re for the other side of the house!”

The blonde working on the house siding is related to the one who worked in quality control in the M&Ms factory. She sent back half the output because they had “W” on them. (Bob Dvorak)