Just wondering, if I take the SIM card out of my basic phone and put it in a smart phone will the smart phone be activated and have my number? Also, will my plan be automatically updated to show that my number is now a smartphone? Or will anything happen at all? I'm on Verizon's Share Everything plan, by the way. This will probably not be what I'm doing to get a smartphone, I'll almost certainly just buy a new phone from Verizon, but I just want to know if this is an option.

I know that Juju and his mom often switches SIM cards between their two smart phones, but I don't know if that would work with an older phone.

Again, I'm almost sure that I'm getting a Nokia Lumia 928. Besides, I can't even find the SIM slot on my grandpa's Droid 2, even though on my friend's, it's right above the battery.

It's possible some phones don't use any SIM card (especially before smartphones nearly completely replaced flip phones), but nowadays almost every phone does. Did you checked behind the battery?

Yep, I checked everywhere I could. I also read somewhere that there are two models of the Droid 2, one with a SIM and one without. SO my grandpa probably has the one without the SIM.