Recently, I stumbled upon Sketch Toy - a web-based drawing tool and Chrome App that allows you to quickly create and share drawings from any browser.
What makes Sketch Toy different from other tools is the ability to not only draw, but also automatically convert your drawings into step-by-step animations that can be shared with a link. Additionally, anyone who accesses your drawing can then add on to it and generate a new link to share, allowing students to quickly iterate on each others' drawings WITHOUT needing an account!
Sketch Toy also lets you rotate your drawings as 3D models and includes a "vibration" setting which makes your drawings appear slightly animated - much like Squigglevision. You can also drag any image from your desktop onto the screen and incorporate it into your drawing.
Cool tool worth a look for DIY video.