Hacky Sack is apparently the trademark name of a type of foot bag. They are a small round bag generally filled with plastic pellets. The one we have fits easily into the palm of your hand (I'm not sure if that's a standard size - or if there is a standard size!)
Basically to play Hacky Sack, you just have to keep the 'bag' in the air using your feet. You can do this alone, in pairs or in a circle.
We recently got a couple of Hacky Sacks free with I think a box of cereal and also in a welcome bag from a bank!
I showed the girls a couple of you tube videos so they could see what to do with them (I tried to show them myself, but was hopeless and they were still none the wiser) . They then tried for themselves - and already within minutes were doing better than me!
I never played this as a kid - but it seems like a great thing to be able to take anywhere to do - inside, or outside. It's another way to get your kids active and moving, and also great for co-ordination skills.
Here's a video so you can see what can be done!
Of course - as with anything, there are world records in Footbag or Hacky Sack that amaze me!
The World record for Mens singles is held by a man called Ted Martin, who kicked the footbag 69,812 times over a time period of 7 hours 38 minutes 22 seconds!
According to Wikipedia (http://en.wikipedia.org/wiki/Footbag_)
I'm assuming that means he kept the ball up continuously for that time, which is unbelievable - how fit would you have to be to keep it going for that long?
Have you ever tried this? Do your kids play it, or perhaps you did when you were a kid?