This is the "Boogie Board". It is pretty much an electronic note pad, but way smarter. You write notes, doodle drawings, make lists or plans or just leave reminders for yourself for later and stick it in an obvious place. I personally found and ordered one as soon as I read more into it and found out how wonderful the whole idea was. When you're done with your note, you just press the button located at the top of the board and it erases the board with a flash (Similar to an eBook reader) and it's ready to be written on once again.
Some things it could be used for range from Shopping Lists, to-do lists, solving your maths problems without using that extra paper, or just a doodling board for when you're bored. The stylus is actually made from stainless steel, but you can use pretty much everything including your own finger to write on the board. It's also pressure sensitive, so the harder you press, the thicker your line will be! As far as the more technical side goes, it's
The only flaw that I could find with this is that some people may actually want to keep the notes they make. This isn't a huge issue for those who don't mind spending a little more money, mind you. For the cheaper version, it doesn't keep the notes. When they're erased via the button, they are gone. BUT if you want your notes to be saved, there is a version which (depending where you buy it from) is about double the price which allows you to save the notes via a USB connection. Oh, and you also won't really be able to read the Boogie Board in the dark, because it is not backlit. So keep it in a well-lit area and it'll work a dream. The other problem is that the Boogie Board does not last forever. According to ThinkGeek, it lasts for about 50,000 erases, which when you think about it is a lot.
(Note, "ThinkGeek", "Amazon" and "eBay" links lead to the main sites, $$ links lead to the actual products)
Although I first found the Boogie Board (without USB saving ability) on ThinkGeek for $34.99 (USD). I proceeded to find it cheaper (and in more colours, which are actually quite nice) on the Australian eBay, for around $40 (plus postage, which, buying from ThinkGeek, would have been a LOT more for us Australians). I also found it on Amazon for $26.79 (on sale!). So, depending on your country, the cheapest option is either ThinkGeek, eBay or Amazon. The Boogie Board with USB saving can be found on ThinkGeek for $109.99 (USD), which is over double the price. For some this could be worthwhile, though.
In the end, this little thing is fantastic. There is times when I've wanted a tablet (which range from $200 - $1000+ AUD) just so I can have something to take notes on. The fact that the Boogie Board exists just for this purpose is simply amazing and I highly recommend to give it a go!