Superstash is an iPad app for collecting and annotating pages on the Web that inspire you. I see it as an app for designers, but it has many applications. The basic idea: snap screenshots of the viewable area of a web page using the in-app browser, add text and drawings on top of them and save the result into your collection. You can organize your shots with tags and/or folders, add notes to the entries and email any screenshot (with annotations) at any time.
It's similar to LittleSnapper, which is great on the desktop, but the mobile version is currently only available on the iPhone. Superstash brings the functionality to the iPad. I've used