Many gardeners are looking for alternatives to chemical herbicides. Here's an option: If you're just trying to rid your driveway, parking lot, play yard and sidewalk of weeds and grass try some boiling water. Pour it directly on any plants you wish to eradicate. They are not likely to survive.
Please note that this alternative to chemicals is not without its own risks.
Hot water is dangerous in its own right and must be handled carefully. Make
sure you don't spill any on the plants you want to keep either!