When comparing Android development to iOS development, there was always one thing with iOS that stuck out as being much better and faster and this was their device emulators (Apple calls them simulators). The Android emulator for ARM is so slow. AndroVM is Android that runs as a virtual machine. It is an open source project which you can download and build or take one of their other builds and use with either VirtualBox or VMware. Once the VM is installed, there is very little you need to do to set it up. You will notice when you start the virtual machine that it is quick. Navigating around the OS is very fast and snappy.
AndroVM is the full version of Android with the Play store and Google apps. This makes it nice so there is no need to sideload applications that you my use for development. If you are developing on it, you are able to change the screen size and pixel density to a number of different values. Upon change you will need to restart but it restarts so fast it isn’t really an issue. This allows a quick look at how your apps or responsive web designs would look in different resolutions. If you are doing native development, it is even possible to push builds straight to the VM from your IDE.