What's the difference between?

[Amaw2008]

What's the difference between: 1 a seagull and a baby with diarrohea? One flits across the shore, the other ***** across the floor, 2 a barrowboy and a three legged dog? One balls out his wares, the other wears out his *****, 3 a bad marksman and a constipated owl? One shoots but cannot hit, the other hoots but cannot ****

[Dedworth]

[Amaw2008]

Here's another one: What's the difference between Twiggy and a counterfeit American dollar? One's a phoney buck; the other's a boney ****