Comment box with spam protection

Anyone know of an easy to use comment form, preferably with Akismet spam protection?  I've got a site that I want to add the ability for users to leave comments like it was a blog.  But the site wasn't created with a blog as the back end.  I coded the site from scratch.  I could go and create the comment stuff, but I'd really like to use something that already exists if possible to save some time.