I think you might've posted about this a loong time ago?

My advice is the same Obedience!! trust me, it is 150% worth the cost if you find a good trainer and you really stick to it!

And, a head halter is basically self explanitory. . a halter that is adjusted on the dogs head, so when the dogs tries to pull on the leash his/her head is jerked backwards. Honestly, I think using a Halti would only be a band-aid on the training issue. OB classes will help you handle this and cure the pulling in a positive way, and it'll help you in many many other aspects too (recall, stays, basic commands, behavior issues, bonding, etc).