The Grinner Knot.
Used in a variety of applications.
Provides a better hold than the blood knot.
BF
<a class="ipsAttachLink ipsAttachLink_image" href="/oldforum/post-19-1100392267.gif" data-fileid="231" rel=""><img src="/oldforum/post-19-1100392267.gif" data-fileid="231" class="ipsImage ipsImage_thumbnailed" alt="post-19-1100392267.gif">
Woops! Just read all the posts and have overstepped myself!, sorry!
Didnt know that was a grinner though...I have ALWAYS been taught that the 'Uni-knot' is how you tie them, and that a Uni and a Grinner are one and the same.
Where is the source for the knots bob?
I too struggle to understnad how the knots differ when finished as the initial twists surely pull out?
however I do find that these twists help the knot pull up better.
For connecting braid I tie it (1) with a round turn and (2) using a doubled over line - ie. in a loop on the end of the line. I got a lot of failures at swivels before this addition.
Adam,
The Grinner and Uni are two different knots if you look closely.
But to confuse things, there is also a knot called the Uni-Grinner. 
I get the knots from various places on the web, but this site has most.
http://www.marinews.com/fishing/fk_main.htm
BF