I've used the Motorola Droid on several occasions, and I must admit that it is a pretty strong competitor to the Apple iPhone. However, after reading my pros and cons list, you will see why I would choose the iPhone over the Droid any day.
PROS (for Droid)
-Physical slide-out keyboard
-Multitasking capable (run multiple applications at once)
CONS (for Droid)
-Physical keyboard is difficult to type on
-Internet browser is far inferior to the one found on an iPhone
-Though the phone has 16 GB of memory, only a preset, small fraction of that can be used to store apps
-Much smaller catalog off apps available for download compared to 100,000+ you can get on iPhone
The verdict: If you are stuck on Verizon, then I would go with the Droid, but otherwise I would pick AT&T and get an iPhone.