American Science and Surplus carries a miniature catapult that also includes plans on sale at their site. They sell many things related to science and engineering.
Online at the website.
You can buy one on ebay or craigslist
buy one
the store
Pondland
toys R us
There are many places that you can buy a hand truck online. Two places that you could buy one online at Sears. Or even from Walmart online.
There are many places where one can buy a HP 99 online. One can buy an HP 99 online from popular on the web sources such as Best Buy, eBay, and Amazon.
One can buy matching luggage online and in stores. For online, one can buy them on Amazon or eBay. For in stores, one can buy them in Sears or Walmart.
There are many places one can buy MP3 players online. They can be purchased from Amazon and eBay either used or new. One can also buy them online from Best Buy.
There are many places where one can go to buy Actionman online. One can buy Actionman online at popular on the web sources such as Amazon, eBay, and Etsy.
If one would like to buy Kayaks online one can get it at several sites. One can buy Kayaks on dickssportinggoods, conquestadventuregear, and also one can buy kayaks on boatstogo.