Flattr widget for current post?

I would like a Flattr widget for each post on my site, but I would prefer to not add the button in a post’s content area. Instead, my custom theme has a “sidebar” (actually a horizontal widget area) that goes near the post comment form. I can add the Flattr widget here, but it is for the entire site. Is there a way I can get this widget to point at the current post as we get when the button is automagically inserted in posts?