If you are refering to inserting the cartridges into the magazine, I favor the HKS loaders. Mag Lula (sp?) has been raved about on some forums also, but I don't have any experience with it.
+1 on UpLULA.I have the UpLula. It works great for both 9mm and .45 ACP. Definitely saves the thumbs and is much faster than by hand.