Cpython optimization

[Qrees]

Hello

As my Master's dissertation I chose Cpython optimization. That's why
i'd like to ask what are your suggestions what can be optimized. Well,
I know that quite a lot. I've downloaded the source code (I plan to
work on Cpython 2.6 and I've downloaded 2.6.3 release). By looking at
the code I've found comment's like "this can be optimized by..." etc.
but maybe you guide me what should I concentrate on in my work?

I've 6-7 month  for this and If I create something decent I can
publish it.

Thank you in advance for any help