Python’s creator describes having too much fun with Python on Nokia Phone:

The phone itself, even without Python, is incredibly cool; I spent much of the weekend using it as a camera, and it worked remarkably well considering that it doesn’t have an optical zoom or a flash, and is “only” 1.3 megapixels…

So on to the vast array of APIs available. Nokia has really done an outstanding job here. There are extension modules that handle all of the phone’s devices: dial a call, snap a picture, send/receive SMS, Bluetooth, and Internet (if your service provider offers it of course); as well as the key applications (calendar and address book, and probably more that I haven’t even discovered). You can also play sounds, view images, draw into a canvas, or open any file that the phone understands natively. And of course the GUI library — menus, dialogs, a low-level event loop, etc. Stuff for which standard Python libraries exist generally uses those — the filesystem (ROM, RAM, memory card, flash) of course, but also the Internet — urllib “Just Works” ™, and you can even write a server if you want to.