The Universal Sign-In Button is a customisable bookmarklet that will auto-fill a sign-in form on the page you are currently visiting and submit it for you. It's a one-click way to tell the current page who you are.
This is simply awesome! I’m such a fan of bookmarklets I actually feel sad I hadn’t thought of doing this before. This simple Universal Sign-in Button tool now greatly reduces the amount of time it takes me to log into IndieWeb and other related sites that offer this functionality.
Signing into websites using my own domain name was an awesome concept, but this greatly speeds up the process and makes it an order of magnitude faster.