Yes, unfortunately you probably have seen many of these, but most of them are either too long, not used the right braid (there are different ones for a reason). To get to the point, this is the one you could use.
Step 1: Get Your Stuff
I have a "SOG" Barrage backpack with a broken zipper pull that I miss dearly :)
Step 2: Construction
Singe the end to a point so you can fit it thru the hole. Pull the ends at halfway and start braiding the "Cobra". Once that is done snip the extra and singe the ends with your lighter.
Step 3: The End
Now you have a fully functional zipper pull!!!