This is way late, but for the record, I thought I'd add one thing, since I'd guess the archive of this pops up for a lot of people wondering. I work in a shop, and the Hozan 4th Hand/cable puller is excellent--though it doesn't have a ratcheting mechanism, per se, it does have a spring-tensioned hinge, which means it locks when clamping the cable. In other words, it can, indeed, be used to clamp and tension the cable and free both hands for tightening and adjusting the cable. I find it a superior time-saver in the shop.
I also have a Pedros version at home, and the thing is, as mentioned before, chintzy. It will serve its purpose for infrequent brake or derailleur adjustments, but I'd not advise it for anyone doing frequent cable work. Its main attraction is its affordability.
Last edited by peripatetic; 02-01-10 at 07:56 PM.