Rands has a great post here, and of course I am going to copy and paste some of it below ;)

Free Electron, the definition:

The Free Electron is the single most productive engineer that you're ever going to meet. I have not even provided a definition and I'm guessing a person has already popped into your mind that fits the bill.

A Free Electron can do anything when it comes to code. They can write a complete application from scratch, learn a language in a weekend, and, most importantly, they can dive into a tremendous pile of spaghetti code, make sense of it, and actually getting it working. You can build an entire businesses around a Free Electron. They're that good.

and, of course, all good things come with their bad...

Free Electron Got'chas:

» There are two classes of Free Electrons. Sr. Electrons and Jr. Electrons. Both have similarly productivity yields, but the Senior versions have become politically aware. In technology savvy organizations, most CTOs fall into this category. Think Bill Joy. The Junior versions have all the ability, they just don't have the experience of dealing with people because they spent a lot of the youth writing their own operating system as a intellectual exercise. These Junior electrons represent the single best hire you can make as a hiring manager. If you get two in twenty years, you're doing something right.

» Misdirected Free Electron intensity can yield odd results. On one project, I assigned a couple of slippery memory corruption bugs to a Free Electron who nodded quietly and promptly vanished for a week. When he returned, the bugs were fixed and the entire database layer had been rewritten. A piece of code that'd taken two engineers roughly six months to design had been totally redone in seven days. Sound like a great idea until you realize we were working on a small update and did not have the resources or time to test a brand spankin' new database layer. Oops.

» Free Electrons sometimes will never engage and they'll never explain why. Free Electrons are high functioning and have a strong opinion about everything... but they may never tell you that opinion. If you're asking them to do something that they don't believe in, they aren't going to do it... ask all you want. The worst case is when you ask a Free Electron to pull of a diving save and they nod in the affirmative and promptly return to whatever they were doing before you distracted them with your useless request One week later, you're going to be expecting the miracle, but the Free Electron is going to plainly say, "Haven't got to that".

One week more, your hair is going to be mostly pulled out, and then you're going to realize you didn't need a miracle in the first place and inaction was the right move. Your Free Electron knew that two weeks ago. He/she just didn't want to take the two hours to draw the picture for you... Annoying, huh? You'll get over it.

» You might expect Free Electrons to exhibit the personality of other uber-nerds, but often they do not. The main Free Electron at Netscape was the most decent human being I've met in recent memory. He also rode a unicycle.

» There are two primary tasks in an engineering organization. Research and Development. While the Free Electron is imminently capable of doing the development, their value in the organization is research. They define the bleeding edge. If you leave a Free Electron in the development role too long, they will vanish and you will have permanently damage the future productivity of your organization.

Awesome article. I often where my Code Poet shirt to work, and it is what I try to live up to with each line of code I write, but now, I think I have a new aspiration in my coding career.