Gripmaster by ProHands
The last time I went to my local music store I bought a Prohand Gripmaster Medium. I always thought that those things were stupid, but somehow this time the product caught my attention and without thinking too much I gave in and bought it.
I thought I could use it on my way back home from work as I go by train. I didn't expect much, but the results are pretty cool.
1) The strongest improvement I feel on the finger coordination side. If you imagine a lick and "play" it on the Gripmaster you have a realistic tension and also an approximate average spacing and measure of a real neck (see the nice aerodynamic shaping on the bottom of the product). This really helps building muscle memory, which is pretty important.
2) Your fingers get stronger. I have figured that while hearing recent recordings of my playing...the vibrato got stronger, the bending felt easier.
3) It's a small unit that easily fits every jacket bag. I have mine always with me.
4) Don't know if I'm going to use this thing forever, properbly not, but so far it did a decent job and the results are there.
"A lot of people in the industry want to blame downloading for the state of the business. But I think if most music wasn't shit to begin with people wouldn't be downloading it for free," - Corey Taylor (Slipknot)