Rated 5 out of 5 stars
There is a much newer version available, recommend using it instead.
snaplinks plus : A revival of the SnapLinks extension for Firefox
Newest version is 1.0.8, released on 24 Jan 2010.
The homepage is http://snaplinks.mozdev.org/
and the newest version can be installed from http://downloads.mozdev.org/snaplinks/snaplinks-1.0.8-fx+sm.xpi
I still rated it 5 stars, as the original add-on was great, and Tommi Rautava was wonderful enough to build upon and release a newer, more feature rich version.