Re: 13.04 installed. I like it but now I'm bored.
If you are really truly bored, then jumping over to Linux is just the right ticket!
You can do lots of customizing with what you've already got and the other contributors have given you some good ideas as to how you can personalize Unity. I'll leave it to you to Google and discover all of the cool things that you can do in just this DE alone.
But if you really want excitement, then you should check out the other Linux distros built more for hacking and experimenting. As you get into them, they will perplex you, confound you, intimidate you, and beat you up, but you will not be bored.
You can start with Arch. If you want a really good bruising, you can graduate to Gentoo. After you try (and fail) to compile your own kernel for the twentieth time, you will find that "excitement" can be way overrated.
Linux. It's not called the hacker's OS for nothing.
Newb: How far must I jump to clear the ledge halfway down?
Guru: It's bad to jump off cliffs. Let's look at better options.
Newb: Stop harping about "best practices" and just tell me.