Feel exactly the same way - am helping friend start a moving business so I can help X days a week whenever the feel arises. But lawn care sounds interesting too.
I figured I pay a guy $50 per week to cut my grass, so right there I would save $1200-1400 per year. Grab a few accounts, get outside in the sun, and shit if it makes me some beer money I'm good with that. I just miss being outside and smelling that fresh cut grass. Something very therapeutic about it. Nothing like putting the headsets on, smoking a joint, and putting your brain on cruise control.
I'm going to be like Forrest Gump, and just cut that grass for free.