I got a Rezap from Todae for $70 that does the same thing - recharges disposable (and rechargeable) batteries including AA, AAA, C, D 9 volt, 6V lantern.
They also have a RezapPro which does more types of batteries
It works, except that if the battery is completely run down sometimes it can't be resurrected - which means that you have to remember to recharge the battery before it runs out in certain appliances that tend to run down batteries completely e.g. clocks. The other downside is that it takes a long time to recharge the battery - I have yet to test how much electricity it uses to recharge one. But overall I'm a fan of the zapper. And it's designed in Australia.
Not sure what the Batbooster can do that the zapper can't but would be interested to find out.
You can check out the Rezap on these sites:
www.rezap.com
www.todae.com.au
A french company released a fantastic new product patented. Not yet available to Australia we are expecting to see the Batbooster coming withing a month. The principle of the Batbooster is to enable recharging the AA and AAA disposable batteries as well as the 9V. THis will considerly reduce the amount of waste of disposable batteries which we know is very bad for the environment especially that considering that only 15% of these batteries are being recycled. THe Batbooster can recharge your "disposable" batteries up to 15 times, so we could potentially reduce the amount of waste by 15 times. I will keep an eye opened on the release of the product and I invite anyone who is interested in this product to contact me so I can keep you posted on the places to buy it from.