Is it possible to upload via sftp for example? Or is it only usable with your hosted service?
that's a cool idea - maybe we'll add that for the pro version - great suggestion. i know i'd prefer that myself.
There are a few free alternatives that has this feature, for example MonoSnap and Skitch (I think).
I use MonoSnap myself.
MonoSnap/Skitch - true. I use that feature from skitch all the time.
There is a great little app for Mac and Windows called LICEcap (http://www.cockos.com/licecap/) that does exactly this. It's free and works really well. I use it all the time.
That said, this project looks awesome for when you need more fidelity than a gif and instant sharing.
Quickcast which is free from app store with no account needed will do this for you.