The best camera is the one that's available

http://www.gizmodo.com.au/2011/04/hey-some-people-actually-use-the-ipad-2-to-take-pictures/

In practice, the best camera is the one you have with you.  That's the only reason I ever use the camera in my phone.  Given a choice, I'd always use my DSLR.  But it's big & heavy, so it usually stays at home.

When something worth photographing appears, I grab the best camera available.  If that was an iPad, I'd use that. 

The photograph at the top of this item was taken using a Palm Treo with a resolution of 640 x 480.