Spotting

I don't know enough about puffballs to do more than ask questions, but here's some info about them on Wikipedia: http://en.wikipedia.org/wiki/Puffball Maybe that will help you identify what you found.

It was just lying in a flower bed right beside my driveway. No trees nearby. I couldn't really see inside the holes very well, but from what I could see, it was dark brown or black inside.

Looks like a puffball fungus, maybe. Was it growing in an open field or under a tree? If so, what type of tree? Could you see inside the holes? What color as the inside?

It's about 2.5-3 inches in diameter. I'm not sure what it's made of, really. At a distance, it looked like some kind of animal dropping, but up close, it looks more plant-like and it has two holes in it, as if it had been attached to a branch, maybe? I've seen one of these before around here, and I feel like a dork that I don't know what on Earth it is.

how big is it? What is it made out of?