Create index for linq to object

When i wrote a custom implementation of Linq to Objects to get a better understanding how it works, (if you are interested see john skeets blog) i thought about increasing the performance of the filtering commands. (especially where) So i tried to implement an index for linq to object and started the LinqIndex project. You can download it from codeplex (LinqIndex)

LinqIndex: (part1) ((part2)) (part3) (part4) (part5)