Quick, easy homemade juggling beanbags

I actually tried this method out for myself this weekend for the first time, in preparation for leading a bunch of cub scouts through this craft. It's really fast and easy, and makes beanbags that are excellent for juggling.

I first saw this via the Texas Juggling Society's booth at the recent Maker Faire here in Austin. I looked for other writeups on the net, but didn't see any that used the bottle trick I'll be describing below. A variant method using a plastic bag is here.

All you need are some balloons (9" or 10" round are good), an empty plastic soda/water bottle, some birdseed, sand or rice for filler, a funnel, and a measuring cup.

I used these specs: 1/3 cup birdseed per beanbag, and 9" balloons.

Steps:

Cut half the neck off one balloon.
Use funnel to put 1/3 cup of your filler in the plastic bottle.
Stretch the balloon's neck over the rim of the bottle.
Invert the bottle to let the filler slide to the bottom.
Squeeze the bottle to force the filler into the balloon.
Pull the balloon off the bottle.
Cut all of the neck off of a second balloon.
Stretch the opening and wrap the 2nd balloon around the first. It's not hard to do. Make sure the opening of the 2nd ballon is away from the opening of the first, so that tension will hold the filler trapped inside.
Repeat with a third balloon for strength and durability.

You can make a set of 3 balls in about 10 to 15 minutes this way.