Can I mirror my iPad's display using the VGA adapter for use in a presentation?
Solution 1:
There's no official way to achieve this.
You have to jailbreak your iPad and use a software like DisplayOut (works on all iDevices) to do this.
Solution 2:
Just for clarification:
With the iPad2, every app is mirrored on the VGA adapter by default, without any additional measures.
Solution 3:
As Studer mentioned, there is no official way to do so. you can use the DisplayOut software for Jailbroken iPads.
If you're more developer oriented, there is also this option