Added https support
The plugin doesn't work on https by default. I whipped in an added a second include for https://twitter.com and bingo, back in action. :-) I can't remember if there's a better syntax, but the second include works for me.
For anyone who wants to do this themselves, edit the file (right click then edit in the greasemonkey scripts manager) then add the second @include line below so the top of your file looks like this:
// @name Follow Cost for Twitter profiles
// @author Barry Hess
// @namespace http://followcost.com
// @description Display a user's Follow Cost right in his/her Twitter profile
// @include http://twitter.com/*
// @include https://twitter.com/*
Barry, thanks for a neat little plugin. :-)
Love & joy - Callum.