Threaded comments, comment's karma

I'm pleased to inform that I just added two new options on polishlinux.org concerning comments:
- comments are now threaded (you can answer a specific comment instead of answering on the bottom of the site)
- comment karma has been added -- comments can be now rated. If you like what someone else wrote, click on the little + sign next to the comment. If you would like to report a comment to be spam,inappropriate,lame or redundant, mark it with - sign.

I hope you like the changes. If you have some more ideas about possible enhencements on the vortal, please comment here. I'd like to make it as friendly as possible.