The Monkey is a program that runs on your emulator or device and generates pseudo-random streams of user events such as clicks, touches, or gestures, as well as a number of system-level events. You can use the Monkey to stress-test applications that you are developing, in a random yet repeatable manner.
The simplest way to use the monkey is with the following command, which will launch your application and send 500 pseudo-random events to it.
$ adb shell monkey -v -p your.package.name 500
For more information about command options for Monkey, see the complete UI/Application Exerciser Monkey documentation page.