Ya, it really is true that there's an app for just about every task.  But the truth is, if I'm already sitting at my desk with my PC turned on in front of me - I just can't think of many things that I would honestly pick up my iPhone for that I couldn't do faster and better with a mouse, full size keyboard, and a full-blown browser... until today.  I just discovered the app for Kelley Blue Book (kbb.com) and it is so vastly superior to the PC experience for finding car values in every way conceivable that I doubt I will ever visit kbb.com again!

What is your favorite smartphone app?