Electric Garden Shears and Shrubbers
If you've only got a little bitty yard that's smaller than, say, 30 square meters, you're going to look pretty silly with a lawnmower. That, and most lawnmowers only get within 5 or 6 inches of the patio, terrace or house, so you'll still have to do something to trim all of that extra grass. This was exactly my dilemma until I discovered the electric garden shear / shrubber combos. I mean, yes, you use a pair of old-fashioned garden shears and manually cut every bit of grass, but you'd look even more silly doing that than you would using a proper lawnmower -- not to mention it would take forever and your back and knees would probably hurt when you were done. But the traditional shrub cutters are too long to really be convenient for "hand cutting" a small area of grass, cos you'd have to get down on all fours to do it, due to the length of the blade (unless you wanted slanted grass). So the following list of electric grass cutters / shortish shrubbers are, in my opinion, the best option for cutting a small area of backyard grass.
Sun Joe Grass Shear / Hedger
I don't want to get all girlie and say this is a cute pair of grass shears / shrubber, but it is! I love the colors and love the design. The Sun Joe electric grass shears are 3.31 inches and the electric shrubber attachment is 5 inches. It's cordless and runs on a Lithium-Ion battery. It starts up right away and there's a light that tells you when the battery is running low. Guaranteed for 2 years.
Black & Decker Electric Shears
Black & Decker is a pretty famous brand and many people like it quite a bit. This particular model has 7.2 volts, is cordless (rechargeable, obviously!) and the battery lasts for about 30 minutes during consecutive nonstop usage. If you've got a very small garden, say 15 or 20 sqm, that's enough time to do the whole thing quickly if you're of a mind to mow your small yard in this way. Otherwise, 30 minutes is plenty of time to trim up the edges where a traditional mower can't quite reach. Comes with a shrubber attachment as well. It weighs about 2 lbs and comes with a two year warranty.
American Gardener Electric Shears
This American Gardener model of electric grass shears has a very impressive approval rating on Amazon.com -- people seem to really like it. Note that it's not a shrubber, but just the electric grass clippers. 4.8 volts and the battery will last about forty minutes in one nonstop go. Reviews indicate that the battery can actually last more than 50 minutes, which is always good.
Original Power Electric Shears
While this may look like the previous model, it isn't! This model is 6 volts, made by a different company and has a shrubber attachment. Another popular set of electric grass shears, this pair is said to be very good at handling all types of grass and making the task a breeze. Battery lasts about 45 minutes after charging and comes with a charger you can hang on the wall in your tool shed.