I'd love it if I had time to sit down and critique your site's design, but I don't. However, I do think the idea is great.

I'm not quite sure the name might is entirely relative to a powerful learning environment. It's the Z in 'learnz'.

In terms of the design, I think you could greatly benefit by comparing your site to the site http://quizlet.com/ . It's a great site with a similar goal in mind, and I think if you can match wits and be competitive with Quizlet, you have some great potential.