I bought my Nexus 7 first gen the week it came out and I don't regret it. There are so many apps that smartphones can use but it's just so much better to use on a tablet.

I mainly use it as something that I can just leave it on the car because its cheap, Nexus 7s are less than $200 right now, and it's ultra portable, I just throw it in my backpack and forget about it until I need it, next to my portable battery charger in case I ever do need it.

The two main differences between a smartphone and a tablet are Battery life and screen size. Some of the functions that are both battery intensive and need a bigger screen are using it as a gps, reading, and browsing. When I'm traveling and I constantly need to know where I am and where I need to go. When I'm on a 14 hr flight, I like to read my books or catch up on HN It's also just an ultra portable, longer lasting laptop. And I also play minecraft on it, and they're working on servers that I can connect to when I'm on my tablet or my computer.

As for a virtual whiteboard, I use evernote, as it has that function, but I haven't really found an app that I really like as a whiteboard.