It's a cool idea. It should save watering costs, too. One of my friends mentioned she had good results with creeping thyme. I personally think some well-placed rocks do a whole lot.

Your neighbors might not love you if they have to try to keep it out of their yards, but I adore creeping Charlie. It's got pretty purple flowers and it smells nice when you walk on it. 

The clover idea is gorgeous. I can't stand mowing, and I have a huge yard which was completely full of sod when I first moved here. I'm on a mission to eliminate grass! Over the years some things I have done to minimize mowing: 

- i turned over several big sections, uprooted sod, and planted wildflowers that are native to my region. 

- the sidewalk strip is finally almost completely grass-free. Nodding onions and chives are there and they're just gorgeous, along with some paving stones here and there to indicate where to walk when folks get out of their cars.  Both nodding onions and chives split really well - you can start with just some small plants and if you split them each year, you can fill out a surprisingly big space in just a few years. 

- In one area near the front, I put cardboard down to kill the grass and then 3 inches or more of playground mulch on top of that. Playground mulch is nice for bare feet, it's soft. I have some potted plants there and my son's mini trampoline and my Adirondack chair where I sit and watch the world go by. And some pretty flags and adornments. this section got a lot of (positive) attention from neighbors when I put it in.

- i installed 3 raised beds 

- I created a rock/gravel garden

- I got the segments of tree trunk from various neighbors taking trees down. Then I created a kind of snaking wall that goes through the side garden. I put cardboard beneath the logs and mulch around to keep weeds down. These pieces of wood are about 2 to 3 feet across, so the "wall" takes up a good amount of space. Another plus for me as a parent is that children like balancing from log to log to log, it's the most attractive play feature in my yard I would say. They give each other challenges and play all kinds of make-believe with that "wall." You could do another version of that with tree trunk "cookies,' they are like stepping "stones" which are just slices of tree trunk. A bed of gravel with some tree cookies immersed in it is very charming.

- I have patches of creeping thyme, which are really nice, but in my climate they don't really turn green until pretty late in the spring. I wouldn't cover my whole lawn with creeping thyme unless the lawn were quite small.

- I'm working on creating new wildflower sections and a gravel area for my son to play in with his toy trucks and excavators. 

each of these has been a lot of work to get set up. But, each year I have less and less mowing to deal with. I think in the next 3 or 4 years I'll be done -- my vision is just pathways, garden beds, wildflower patches, and play areas-- once that is in place my yard will just need weeding. I love weeding, but actually I don't have much of it to do now that everything is so established. In a few years my yard will be sooooo easy! And the vegetable gardens do take a lot of water, but other than that, now that the wildflowers are established, I never water. 

I went with synthetic turf. No mowing, no water. The stuff looks amazing these days. You can't tell it's not real just looking at it. Great for my dog. She no longer pees on my patio pavers. The stuff is made for pets with a drainage system with silica granules underneath.