Question: On iOS devices you can take a screenshot by pressing the home & sleep buttons at the same time. Is there a similar way to take a screenshot with Windows Phone?

Answer: 
There are a few ways to take screenshots:

1. If you're just a developer and just want to take screenshots for marketing your app, you can use the [emulator's screenshot tool](http://msdn.microsoft.com/en-us/library/gg442300%28v=VS.92%29.aspx).
2. If you have a developer-unlocked phone ([$99 a year from Microsoft](http://create.msdn.com/), or via unofficial tools) you can use [third-party apps like the one described here](http://www.winsupersite.com/article/windowsphone75/windows-phone-75-screenshots-141063).
In Windows Phone 8 you are able to save a screenshot by holding both the power button (often on the side of the phone, between the volume buttons and the camera button) and the home button (the middle button under the screen, with the Windows logo on it) for some time. Such screenshots are saved in the Screenshot album of the Picture Hub.

And just to be complete: in Windows Phone 8.1 Preview this combination was changed to holding both the volume up and the power button. If you use the older Windows Phone 8.0 key combination, you get shown a message box that tells you of this change.

For normal users (no developers) in Windows Phone 7.5 and earlier there is *no* way to make a screenshot of your phone except using another camera(phone) to do it. I think this is still the case in the Windows Phone 7.8 update that brings the smaller home screen tiles from Windows Phone 8.