of course you can double knit it!
first off, there is the Hoover blanket (search the archives of Knitty.com) its a knit in one go blanket.
then search my archive (on blog) --Mid april to mid may (07) for some info on double knitting, including a tutorial, a YouTube (for 1 style of cast on (i also write about 3 others)
i tend to make potholders (though anyone on ravelry can check out my projects, i am oftroy there too, and see my vest and one of my hats)
and what are pot holders but 'blocks'?
if you are on ravelry (or live in NYC area) there is
1--a ravelry group for double knitting
2 a class scheduled at Knitty City (west 79th street) on double knitting.--i forget the instructors name, but i am impressed with his work!
when i double knit, i tend to do Jacquard (2 color, both sides of work meshed) work.
but you can also so "motifs' (the 2 sides are only linked together at perimeter of design) or textured (knit and purl) designs.
there is a double knit pattern for Horizontal stripe on side A, vertial stripes on side B too!
info and resourses on double knitting is sparce and scattered.. the internet might be your best resourse!