When we were preparing the case for our "Library on Location" trial, and again when we were writing up our results for the conference paper, we did a literature review - both journals and blogs. I thought we'd been pretty much as thorough as the variable terminology people assign to the concept allowed.
But I just saw a tweet linking to Theoretical Job Description for the Librarian with a Laptop, which links back to where the blogger first had the idea, which in turn links to someone else with the same idea.
(This last one is a really really great idea for implementing it at an academic library with maximum success.)
It's not uncommon for me to see the occasional new one, but for some reason this hit me with a "Argh, we librarians really like reinventing the wheel, don't we?" At one point I was vaguely thinking of doing a survey of libraries who'd done this kind of thing in order to write up a journal article about success factors, but stuff happened. Suddenly I'm all fired up again and just have to work out how to pull myself back from impending overcommitment...
In the meantime, my collection of links about libraries that have done outreach by taking books and/or laptops outside the library to meet users in popular locations is at my "onlocation" tag on Diigo.