Ok guys. My roomate explained this to me, and I REALLY want her to be
wrong.

If I use grass clippings as mulch in my garden, am I just planting
grass in my garden?

I have an awesome arrangement with my neighbors to get their lawn
clippings, so I have piles and piles of fluffly, beautiful lawn
clippings - and more coming every week, as my neighbors mow their
lawns. I don't want to put them in the compost since they will take a
few months to degrade, but I REALLY don't want to plant grass in my
garden.

It breaks my heart to just throw it into the compost.