>You don't want to do this, believe me: If, perchance, you lock up the
>rear wheels, the vehicle will spin around. And if you happen to be moving
>at any speed, the spin will be sudden and violent. But if you to decide
>to try it anyway, be sure to hold in that little button on the end of the
>brake handle so that you can release it quickly when all hell breaks
>loose.

You're rear end will come around but only if you are on a curve or the road
has a pronounced crown.  If you are in a straight line and the road has
little or crown the vehicle will remain straight.  Why?  It has to do with
angle of momentum as it relates to angle of the force resulting from rear
brake application.  The resulting vector, while traveling in a straight
line, is more or less perpendicular to your direction of travel.

Obligatory FRIDAY comment:

I've tested this on many occasions.  A combination of long nights delivering
pizzas, boredom and rain.  "Ugh, sir, that's our new SCRAMBLED pizza.  You
like?"

Chris,
'85 Westy.
Usual disclaimers apply.