Question: do any of you run things like Foreflight on the iPhone or other smartphone? Is it worth it, or better to use it on a tablet?
For in-flight use, you want an iPad. But since ForeFlight lets you run multiple devices with a single subscription, it's worth having on your iPhone too. A few things in particular that the iPhone is quite good at with ForeFlight:
1) Calling ahead to FBO's. Tap the airport in your flight plan (or type the identifier), tap FBO's, tap an FBO name, tap their phone number, call. Since you have to do all but the last tap to find their phone number anyway, it's quite handy.
2) Checking weather. You'd think that a smaller screen would suck at giving you the big picture, but it's kind of the opposite. The smaller, lower resolution screen can give you a wide-range radar picture, show a ton of METAR results, etc. just fine. Turn on Radar and Ceiling (or Flight Rules) overlays and you can get a pretty good big-picture weather situation. Tap the dot over the airport to see the METAR. Or, if you're wondering whether to head to the airport at all, just tap "Nearest" in the menu to see weather at the closest fields. Tap one for more details.
Okay, those are my favorites. But, the iPhone version can do just about anything the iPad can do, just smaller! Always good for when you aren't carrying the iPad around 'cuz it won't fit in your pocket.