I really like the idea of a keyboard friendly task app. Here's some feedback. Hope it helps:

* signup didn't work for me. When I submitted the form, it just took me to the signup form again. EDIT: I think it's because the username I wanted was already taken, but there was no error message telling me this.

* login link didn't take me anywhere

* It'd be nice if '?' brought up a list of keyboard shortcuts - similar to what google apps does

* It'd be nice if shortcuts could be customized

* A call to action in the anonymous list to signup to save the list makes sense

* jumping between the list, settings, and sharing tab with keyboard - maybe control-shift-1, 2, 3

* the UI is slick and simple. I love it.

* how do I delete a list?

* can there be labels / colors?

* will there be an API to access my lists?

* make links in tasks clickable