I searched around for this and didn't find anything. I guess it is something so simple that nobody has bothered before.
The idea is to create a block with just a simple "Add content-type" button. For user interface, I like to have an add button in the same context as view content.
EG. if you have a view of News Releases, it is nice to have an "Add News Release" button at the top of the view. In the same way that a user can just go to a page and edit, they can just go to a view and add a new node.
I've thrown together a quick module for a project but I wanted to get feedback first. It is permission aware, so that you don't see the button unless you have the permission to create that content type. I'm half expecting to hear that it already exists, but any feedback is welcome.

Comments
It'd be a nice addition to
It'd be a nice addition to the "edit-export-clone" links that already pop up on hover over a View... Does your module take into account the fact that a View could contain nodes from multiple content types...?
I didn't think about adding
I didn't think about adding it to the context links. I think they are potentially confusing to an average user and better suited to a power user or site admin. Maybe that will be in the 2.0 version :)
I do take into account multiple content types... Say you have 5 content types, but only want blocks for 3, you just check those types off in the admin screen.
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