Easy sharing of SSH keys
This tip may be obvious to many people, but I feel this worth mentioning. A lot of us have SSH keys set up for github. I found out today, from a friend (github/sakshamsharma) that you can actually share your public keys with others by giving them your github username. For example,
curl https://github.com/pallavagarwal07.keys >> ~/.ssh/authorized_keys
would give me ssh/scp access to your PC.