I recently just started using these: http://www.fatgripz.com/ They are great! If you have been wondering how you can improve your forearm musculature and grip strength then look no further. Sounds like I'm making a sales pitch for the company but I'm not, I have no affiliation with them at all. Just tried the product for the last few workouts and am very impressed with the way they hammer the grip. It feels like 20lbs are added to the dumbbell when you use them. The drawback is of course shortchanging the muscle group you're working that day. For instance today was back day and I used them to start out with pull ups. Got maybe half the amount I can normally do. Then went on to barbell rows with 1 plate racked and my grip was slipping after only a few reps. So I've been thinking of ways of incorporating them into my routine without shafting other muscle groups. So far I've used them on chest/biceps day, some shoulders, and now back. Any ideas?