In all seriousness, Butt-Ups are very effective in strengthening and toning your abs. One of the best parts is all you need is your body, no equipment required. Additionally, you receive the benefit of strengthening your upper body and stretching the back of your legs.
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1-Begin in the forearm/elbow plank position. Make sure that your elbows are directly under your shoulders and you are reaching through your heels in order to create length in your spine. Engage your abs and your glutes, imagining that you are bringing your belly button to your spine. This will minimize the arch in your back.
2. Begin raising your glutes to the ceiling, further engaging your abs in order to minimize the distance between your ribs and your hips. Continue to maintain length in your spine and activation in the back of your legs.
3. Now, slowly and with complete activation of your abs, bring your glutes back down to the beginning elbow plank position described in Step 1. This is 1 repetition.
4. Do 3 sets of 20 reps.