Hmm- backpack-style vacuums. News to me, but why not?
http://www.vcdiscounter.com/backpack.html
But wait, there's more!
Is this for indoor or outdoor use?
Of course you've googled it. I just searched 'backpack vacuum review' and got this:
http://www.consumersearch.com/www/lawn_and_garden/leaf_blower_vacs/

I'm not really the vacuum expert- just a typical, slovenly bachelor with a Roomba.