The android OS is starting to appear on other Linux based devices showing how versatile it is. The first is the Nokia N900:
The project link is http://guug.org/nit/nitdroid/. The next is the iPhone 3G:
More information can be found here: http://linuxoniphone.blogspot.com/2010/05/iphone-3g-binaries.html. Although these are not ready for every day use, these projects show that it can be done.
Finally, Android has even made it on to Windows mobile devices:
More information can be found on this XDA thread: http://forum.xda-developers.com/showthread.php?t=623792
The fact that Android is an open source OS means that people are able to do more interesting things with the platform. It will be interesting to see what other devices Android appears on in the future and what other shapes the platform will come in.