The idea is great, but a lot of fields are filled with wrong values: for example usernames end up in the referrer and passwords in the confirm email address. We use Jumbastic Forumsurfer. There everything works fine.
And you can fill forms with one click.
This is a pretty good script, except you can't use it to fill in specific radio buttons or drop down menus
It works well, it enters all the registration info you provide to make registrations a faster process. Perfect for signing up to forums for single posts etc.
There are quirks. It can often enter the wrong info into the wrong fields, like name into the referrer field, or screwing up the timezone field, or for whatever reason unticking boxes that are usually checked by default which I assume is for spam email prevention, but it can untick useful boxes also.
All in all, a very handy script, that would be even better with a few bugs ironed out, and a more autonomous autofill, rather than having to manually find and select autofill.
it does well for registration type. However, for the type of forms (like web app), it doesn't record previous entered data, and allow to submit. And if you plan to do that, please allow to save using different name, so people can select which one to fill. Also, the menu is several clicks away in FF7, so I would rather see it more prominent somewhere when enabled.