Post link in new window

I was just wondering is there a way to make only the POST links open in a new window. I know that if you put

<base target=”_blank” />

in the header it does it, but it also opens any other link on the site like the comments link etc open in new windows, when what I really want is just the links in the posts to do that. If anybody knows how, or alink to a how-to that would be great…?