I found this website through...I don't remember. Hmmm. Well, anyways. I love it!
You don't have to sign up, but it's free and you get more use out of it if you do.
Once you sign up, you can import your own favorite scriptures to memorize or use the ones they already have available. Then you 'type it' - type out the verse as you read it, 'memorize it' - type the verse with every other word taken out, and 'master it' - type the verse completely from memory.
I hope you try it and that it works for you just as well as it does for me!
(Click the image above to go to the website)