Adding fields to registration

When people register on my blog.

http://www.advertsports.com/blog/wp-register.php

They are only asked two things. I want ask for more details (e.g. add more feilds) and make certain feilds compolsary. In particular what country and state they are from?

Is there a plug-in that can do this e.g. add the ability to add new fields to registration and either make them compolsary or not, or does it have to be manually editted in php?

Furthermore how can you get the registartion page to sit with in the site template? Instead of seperate page