• http://ifconfig.me
• http://smart-ip.net/geoip
• https://zmap.io/heartbleed/
• http://mashable.com/2014/04/09/heartbleed-bug-websites-affected/

Plugins to check for heartbleed on websites one visits:

• https://addons.mozilla.org/en-US/firefox/addon/foxbleed/
• https://chrome.google.com/webstore/detail/chromebleed/eeoekjnjgppnaegdjbcafdggilajhpic

• https://cacert.org