is_post or equivalent?

Howdy guys,

I want to place a link for a RSS feed for comments for each post within a sidebar, now as a result I need to determine if it is on a post page to display the link to the feed..

http://www.yawnster.com/

If you take a look at the sidebar on the homepage, it defaults to the last post made, I wish for that to disappear and then only reappear when on the post page.. (http://www.yawnster.com/2007/06/11/openid/)..

Is there an easy way to do this, I was assuming there would be a built in template function, but my searches are drawing a complete blank.

Thanks in advance, Alex.