How To Practice Guitar!

I dug up an excellent / incredible website.
It makes practice exercises for you, based on how you specify.

My StumbleUpon button yielded a list of guitar practicing websites, all I was aware of, except for this one.
At the website, guitarcardio.com, you're given options of root notes, scales, modes, and difficulty. You tell it how many you want it to generate, and it generates them.

The exercises are clearly helping me. They're a challenge - that's key to improving.
I'm doing medium difficulty ones. Some are harder, some are easier - it's about where I'm at. It's clearly helping my fingers to be more coordinated.

It seems to be the guitar equivalent of my Hanon piano books.