This blog post from Bitovi offers a wealth of information on JS memory leaks.
What is this JS memory leak anyway? Douglas Crockford has this explanation. Another interesting info from Quirksmode. And one fine explanation here.
Please take time to read this post by Brian Moschel.(@brianmoschel)
You might also want to checkout TodoMVC. It offers a ‘Todo’ application implemented in various JS MVC frameworks.