Provide feature to copy from the web & paste into an outline like with with Diigo or OutlineEdit
Diigo or OutlineEdit let you copy text from a web page & insert into an outline. They have browser extensions for this.
Adminsashika (Admin, Checkvist) commented
Actually, you can copy and paste from the web (here's a blog post about it: http://blog.checkvist.com/post/172989232788/copypaste-improvements-for-text-and-attachments).
Also, Checkvist has a bookmarklet and a Chrome widget -- https://checkvist.com/auth/profile#tools
Is it what you were looking for?