Saw this article today and all I could think about is how well this concept would apply to the high profile signings and potentially photo ops at conventions like this.
http://www.huffingtonpost.com/entry/universal-orlandos-jimmy-fallon-ride-eliminates-the_us_58e7b56ee4b06f8c18beeb2b
" The Official Universal Orlando app allows guests to make a reservation for “Race Through New York Starring Jimmy Fallon,” and reserve a spot in the virtual line. Nothing new here. Disney pioneered this system with FastPass+ that allows you to reserve spots for attractions through its MyDisneyExperience app. With Universal’s Virtual Line, when your turn to ride arrives, you head to the “NBC Studios” entrance, and that’s where Universal got really clever. You enter “NBC Studios NYC 30 Rock” facade, receive a colored Peacock card, and continue along on your Studio Tour. The color on your Peacock card corresponds with lights throughout the studio. When the lights change to your color, it’s your time to board the ride. But what do you do in the meantime, stand and wait in line? Nope. You’re free to wander about the first floor Memorabilia Hall filled with props and artifacts from each and every era of The Tonight Show ..."
The latter half of that is just like wandering around the exhibition checking out vendors.
And to address the phone signal issue...why not have WiFi available? And phone charging stations too...phone charging stations are a given at most major gatherings nowadays.