For many plants, coffee grounds would be too hot. But grass can handle a fair bit, provided you don't clump it.
Myself, I think I would rather run it through the compost first. Mostly for ease of fooling with it. Plus, since coffee grounds are high in nitrogen, it is possible that some of the nitrogen might escape. A compost pile has a better chance of capturing it.
Just joined but throwing in my .02 on this old thread. i was doing this back in the late spring, early summer. Picking them up from Dunkin 5 gal at a time and drying them in the garage. Spreading by tossing in the air from a cup, VERY thin like. Not sure why but i noticed it formed a barrier in the bare spots that wouldn't let rain water soak in. Every time it rained or i watered i noticed it was flowing off of the lawn. I had to go back and rough up the bare spots. I was having a hard time getting grass to grow there due rain run off from the gutters. I have since stopped using them until i can get my compost tumbler heated up more. Just my experience. KB
I dump my coffee grounds out in the yard each morning. I use organic coffee and fill my coffee press with cool water to mix them up, then dump it at the base of roses, hibiscus, grass anything that looks like it needs nutrients. I haven't had any dead spots in my yard and have gotten more blooms from my flowers from using it. We have really poor clay soil here, so it just loves this taste. I have never done large amounts at one time, so this might be why I don't have the oil issue like the other poster.
Another method with using the coffee grounds is to steep them in a bucket for a few hours, and then use the liquid on the lawn instead. Scatter the grounds around plants and vegetables to keep down snails and slugs.