I maintain vigilance.mit.edu, which is the oldest more-or-less continually running webcam server in existence.
I helped write the 2014 MIT Mystery Hunt
I wrote my undergraduate thesis, titled "Optimizing Tensor Contractions for Nuclear Correlation Functions" with Professor Will Detmold.
I took 8.231 (Solid State Physics) and wrote a paper on the anomalous quantum Hall effect.
I did more Junior Lab this semester. You can read my papers (with Sabrina Pasterski) for Quantum Information Processing, Doppler-Free Spectroscopy of Rubidium, and Superconductivity, as well as a final project on demonstrating Bell's inequalities in a liquid-state NMR system.
For 8.06 (Quantum Mechanics III), I wrote a review paper on Quantum Dots, along with a simple Mathematica model of their behavior.
I took Junior Lab and wrote papers about physics experiments. You can read my papers (with Jenelle Feather) for Pulsed NMR, Optical Trapping , and Relativistic Dynamics.
I wrote a paper for 6.869 (Computer Vision) about analyzing games of pool from youtube using computer vision.
For 6.867 (Machine Learning) in fall of 2011, Cathy Wu and I wrote a sentiment analyzer that can identify reviews as positive or negative.
For 6.892 (Interactive Theorem Proving) in fall of 2011, I implemented a series of algorithms with automatically verified running times.
To help learn Haskell, I wrote a small raytracer. It's not particularly neat or fast, and I plan to rewrite it at some point.