Amazing never the less!
At the moment, it's paying most of my bills while I work on something much bigger ;)
(just a few)
1) The annoying one - When backspacing over values in entry fields (such as opacity, or distance), backspacing over all the characters causes NaN to appear in the field. Sometimes you have to fight with the input field a bit to allow you to re-enter text. (Usually shift+home+the key you want to hit will work)
2) If you enter a ridiculous value such as 500 for percentage then the slider behaves strangely. Not annoying as it pretty quickly snaps back to where it should be.
I love the site, so please do not take these two critiques as a slight against it.
Really nice tool, good job!
Props should also go to http://www.colorzilla.com/gradient-editor/ who have been doing things like this in the past.
That site also generates the IE fallbacks as well.
Though i'd contest the assertion that it uses my 'favourite graphics editor', my 'graphics editor' would be more appropriate ;)