Not only does to require an account to use, but you can't even sign up. Plus it looks to be paid.

Excellent idea. i Love the concept. Now i can optimize my research process highlighting the information i need as i browse between multiple pages.

Interesting.

I was waiting for Firefox version since the release for Chrome and finally it's there.
It's very fast and robust, I have a feeling it works even faster than on Chrome.
Would be nice to have email integration though.

You can grab links, images, make page screenshots easy and see it later at shelf.io