Thanks! I made them using my standard equipment (a.k.a. my camcorder on the 'voice recording' setting), a clothes hanger, and several sticks of wood of various shapes and lengths. Then I just edited them into shape in Logic Express.

Thing is, you have to swing the object (wood, hanger, whatever), at the right angle, or else all you'll get is that 'krrr' sound of wind hitting the microphone, even if you have a wind noise control option on your equipment (like I do). Generally I find it's best to swing the object at a 90 degree angle to the recording equipment, but it really depends on the equipment you use.

Here's a diagram of what I mean. My camcorder has a flip-out screen that has the microphone on the back. I'll lay the camera on it's side and swing the object above the screen, like so:

--->--->swing object --->--->

O
O
#
# <-- microphone
#
O
O
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXX <--camcorder body
XXXXXXXXXXXXXXXXX

Hope that helps! =)