Detect selection via touch or mouse click on a GameObject/Sprite?

Hi. I've been searching and watching some of the new 4.6 videos, etc. It isn't clear to me what the best way to handle this is.

Put simply, I am going to have a few 2D sprite objects on the screen. I want to create a unified way of determining if a character is either clicked (mouse) or touched/tapped regardless of whether it is running on a tablet or on a PC/Mac.

Can someone point me in the right direction? Not asking for anyone to do my homework for me.

Thanks!