Hi,
An even greener alternative is to get one of these:
($120 with free shipping at Amazon - click for link)
Our Little Acre: Gilmour Reel Mower RM30 - A Review (Part I)
Our Little Acre: Gilmour Reel Mower RM30 - A Review (Part II)
20" width, ball bearings, self sharpening, spring-loaded blade tensioner, straight handle -- I got two of these for my Quaker Meeting and they work very well. You can use the clippings catcher for small areas, but for large areas go without it.
[Edit: these are much quieter than a power mower, but they do make some noise. Pushing them is pretty easy -- no harder than pushing a non-propelled power mower. If you stay ahead of the growth, you'll be fine -- and if it gets too long, I use a grass whip (double-acting scythe) afterwards!]