How to strengthen grip?

Not sure if its been mentioned but I built grip and finger strength by just repeatedly trying to crush a tennis ball. Seemed to work pretty well and I could do it while watching TV

 

It also worked build up Gene Tunney's hands if you believe the legends..

 

WIN

 

Are there any gyms with anvils? Doing deadlifts has increased my grip strength for, err, deadlifts but I went back to mostly parallel grip palms inward and today managed 3 reps at 90kg which is my max DL on my weakest grip

 

Apart from actually going to purchase stuff, like these in a extreme sense;
http://www.nkb.com/motor.htm


Simple use of easy to find simple-budget items such as;


However, be warned;

Whenever certain parts of the body are over-stressed, there could be future detremental effects from the long term, for example lack of dexterity.

http://ergonomics.about.com/od/treatmentprevention/tp/prevwristrsi.htm

 

Rope climbing maybe worth mentioning, or pulling stuff with a thick rope (prowler, small car, fat people etc.)
As of next week I'll be holding a 100 kg Deadlift at lock out for a wee while to try improve my grip (3 sets.) I'll let you know How I get on.