I recently purchased a "fat bike." Think 4-inch tires.

It may be the most versatile bike I've ever owned. Pump up the tires hard and I happily commute to work on it. Let some air out and I ride local Singletrack dirt trails with ease. Let more air out and I can ride on the beach or snow.

Can I ride it as fast on pavement as my road bike? No.
Am I as nimble on trails as on my full-suspension mountain bike? No.
Can I ride terrain I would never attempt on any of my other bikes? You bet.

And it cost between 1/4 and 1/6 of what my high-end mountain and road bikes cost!

(I'd post a photo of the bike if I knew how. Anyone know how to get a photo off of an iPad and directly onto the forum?)