Comments are something many want to have open on their web site, but comments on pages and/or posts are sometime not wanted on a particular blog post or page on your site. Did you know you can turn on the ability to disable comments (along with pingbacks or trackbacks) at the single content level?
At the top of the page, for both posts and pages, is a screen options tab. Once this is clicked on you get the below image (discussion option outlined for each):
With the Discussion option selected, you will see a new metabox appear in the right hand column (by default).
With this in place, you can turn on comments as a general setting ( Settings > Discussion), but disable it on a post or page level, where you wish to disable it. Enjoy!