Quizlet : Nice learning tool.

I some how stumbled on it, and was astounded by it. Its high on simplicity, and is pretty useful and addictive. Three things which I reckon are essential for a good startup, or any new web service. Though there are always more things required to make a killer product, but for a successful product the above three things are very important. But this is not why I was astounded while going through Quizlet, I would tell it after I finish what Quizlet is all about.
We all know that flashcards are nice learning tool, if you didn't knew about it then also Quizlet will keep you busy, why? just because it is informative in nature. It is very simple flashcard using tool, you can create a set of your flash cards, and then use it for future use, and keep on using them. But thats not all, yes, its social, which means that you can learn from others flashcard. Not only this much but it also provides multi user editing, much like a wiki. So your set an be more than your set but can be your groups set as it also provides option to create a group. Since it is focused on vocabulary building and similar things therefore a simple statistic tool also works beautifully.
Now comes the astounding part, this whole website is a brainchild of a child, rather I should say teen, his name is Andrew Sutherland, and is just 17 and launched Quizlet when he was 15. As he has mentioned, it took some 420 days for him and him alone to make Quizlet, and few more days to become president of his startup firm Brainflare.
Thats not all, what I found more admirable was outlook towards his job, he does have a definite business plan for Quizlet, in his words...

Quizlet is free and will remain free to all users. The current plan is to offer targeted advertising on the non-studying pages. I'm hoping to make some deals with some educational and test-prep companies and perhaps some universities. If you're interested in advertising to my userbase of highly-motivated high-school and college students, shoot me a note (see above right).

For future I wold love to see its mash ups with flick images or Google maps and anything else, which can make it more interesting. Much higher on want list would be a web widget of Quizlet which we can put on our web pages or blogs. He is an intelligent kid, what it seems from here, and soon we may fine such things.