I never though I’d use one of these, but for threading
They come in all different shapes, sizes and designs. The classic one works good enough.
Also relevant are big eyed beading needles.
For sale on amazon >> http://www.amazon.com/Set-Big-Beading-Needles-Sizes/dp/B001B2M658
Here are some of the different designs:
There are also lots of instructions on how to use them: