Here is one where the yo yos are sewn to a quilt top
http://www.amybutlerdesign.com/pdfs/Bloom_Quilt.pdf
here is one where they actually put fiberfill inside the yo yos.
http://mousechirpy-polkadotpineapple...-yo-quilt.html
And here are some projects using yo yos.
http://www.allpeoplequilt.com/techni...jects_ss2.html
I believe that if you make a yo yo coverlet without backing, you lay it across another blanket; but if you attach your yo yos securely on all four sides, I don't know why you couldn't use it like any other blanket or quilt. I'm really liking the idea of putting the fiberfill in them!