For years I've been using a collision system that involves each object having a radius and checking if the distance between the two objects is less than the sum of the two radiuses(radi?). Essentially it uses circles instead of boxes for collision checking. It works rather well for 2d space sims and any game that uses a top-down view. But I don't know if it's a common technique and if it is I'd like to know what it's called.
Also are there any significant drawbacks to using a system like this?