Java Chat - I made this over the course of a weekend, learning about Sockets (Actually quite easy, when you wrap your head around how it works.). Definitely making a tutorial later on after I upload this. When you "host" the server, you should forward port #7777, which is used by default by the program. Might work without forwarding, I dunno. Here's the source (Commented and everything. Almost obsessively so!): Java Chat Source. Note: Server and Client are separate projects, so remember when opening in Eclipse or similar.
Noise Terrain Generation - A very interesting topic and project that I will be making a video on in the future if sufficient interest is shown. The terrain generation code by itself is adapted from this article: http://javagamexyz.blogspot.com.au/2013/03/terrain-generation.html. This is a really interesting article since it describes precisely what it does. The code itself is also incredibly easy to integrate into any sort of map/terrain generation system. Only took changing a few variables and I was good to go.