Recently attended a non-competitive hackathon on Ethereum and smart contract development, where I discovered Vyper, a promising alternative to Solidity.
Crypto Currency Portfolio Tracking Tools
I own a few different kinds of crypto coins and like to keep track of their prices and the current value of my portfolio, so I wrote two tools to help with this. One is called Cryptfolio and helps you track your portfolio's current value (yes I know there's apps that already do this, but hey I'm a geek and had to write my own ^_^ ) You can find it on my Github here: https://github.com/gloriasilveira/cryptfolio
And another tool to track the current prices of any coins of interest: https://github.com/gloriasilveira/crypto_price_checker
Open Wireless Router Hardening
I participated in the Riscure/ThoughtWorks/EFF's Hackathon by conducting code reviews on the Open Wireless Router in order to help make the internet a more open, private place for everyone. Details are here and here
Failure Testing/DDoS Attack
I recently set up a basic web site in AWS (three web servers behind a load balancer with a separate back-end database) in order to do some stress testing and server attacks against my test servers. I used Netflix's Simian Army (and more specifically, their Chaos Monkey) for failure testing, and also BeesWithMachine Guns for a load test/DDoS attack.