Collaborate on a website or other graphic with Twiddla. Twiddla is a free tool that allows you to meet with others and text chat (or even audio conference) while drawing on a website, image or other type of document (pdf, doc, etc). It is free and requires no signup or login and no download or plugins. The service is browser agnostic and requires no special setup.
Just go to Twiddla, click GO and click Invite (or simply share the URL of the Twiddla page with anyone you want to join). It’s really easy.