THANK YOU VERY MUCH!
Nice idea, but after using it for about a week, I've found that it's more inconvenient than helpful. This will save your input into all HTML forms, and upon revisiting the site, will display a light red box in the upper right corner with the number of "redos" available to you.
I installed the script hoping to save my input on two specific sites, a blogging site and my webmail. Both seem to use input fields that this script does not catch. At the same time, this script catches all search terms entered on many different pages. Of course the script can be disabled on those pages through Greasemonkey, but I find that doing so is not worth the effort, especially when the script cannot catch the two input forms I was hoping it would.
Other than that, the script works as advertised, and could be a great help to some people. Just not to me.