What you do is
1 open a free account at SimplyBox
2 use the SimplyBox (box and save) button to select anything you´d like to keep or have a look later.
3 after selecting the image you want to capture, you can drag it to one of the boxes you have created.
- you can integrate SimplyBox with your twitter account so that everytime you box something it´s sent to your twitter followers as a link.
- you can also share your box with other people, then many people can drag nice discoveries into the same box.
I also use Diigo for bookmarking, but what I found in SimplyBox is the possibility of seeing images of what I have bookmarked. This way, I can recall what it is about without having to write a long description.
This is a great video which explains how it works