What are the key differences between Android, iOS and Blackberry OS?

What are the key differences between Android, iOS and Blackberry OS in terms of level of accessibility by application developers (i.e. access to the video input, sound input, phone functionalities, to which extent, etc.)?

PS: Assume latest version of each OS.

EDIT: Can someone turn this into a wiki so we can compile answers from people that don"t necessarily have experience in all 3 plaforms.

I'm not familiar with BlackBerry, but on Android and iOS you can access just about anything. Until recently iOS had some restrictions about camera access (see this), but I belive those have been solved. Because Android is open-source, you can theoretically go as deep as you want as far as accessing the hardware, but you may or may not be able to get any deeper through the standard Android API than you can through the iOS API.

On Android, you can do a lot more to override default functionality. For example, you can create your own launcher screen or phone application. The iOS approval process wouldn't allow these kinds of applications.

API hardware access really isn't an issue on either platform, the bigger concern is overriding default software (almost never possible in iOS) and what types of applications iOS allows.

Each platform has its own nice and bad parts. I have been working on both Android and BB. I wish I could take only nice parts from both to create a platform of a dev dream! :)

For instance, I could take these features from BB:

1. The greates feature I like in BB is the simplicity of the application architecture - you can always count on your main UIApplication instance - OS never kills it.
2. Also I do like the simplicity the Dialog class provides - it is very easy to implement business logic related to user choice - while Dialog screen is shown the code execution just stops and waits for user input.

From Android I'd take the following:

1. Network communication. On BB this is a real nightmare (BES, BIS, WIFI, Direct TCP without APN, Direct TCP with APN, WAP, WAP2, Unite - who's next? :)).
2. For file manipulations you just use a native/usual Java API.
3. Nice looking UI components are available right out of the box.

I should add I'm not happy with GPS related stuff on both platforms, however maybe it is due to GPS hardware limitations rather than API creators.

Thanks!

BlackBerry is a pain, once I made a project for it (the JDE version was 4.7 back then) and it didn't had an ArrayList. WTF?