Tattoo ideas?

So I have a tattoo of this on my left upper arm. I'd always wanted a tattoo, but I could never think of anything sufficiently awesome and original (well, "original-ish") until a year or two ago.

I love this one, but it's not very colorful. I've been trying to think of something equally nerdy and cool, but with some more color. Since I work on software for printers, I'd considered maybe a color gamut, or maybe a colorized DCT basis function to commemorate the years I worked on image compression. But I dunno, those aren't cool-looking enough.

Awesome tattoo, or horrible skin disease?

I recently had the idea to see if I could think of a way to do a portion of the Hubble Deep Field image, but then I realized it would probably end up just looking like a bad rash.

That might be a line of thinking worth exploring though, and I have a couple of similar ideas pictured below. The famous Eagle Nebula image is a candidate. The M100 Galaxy is also cool, but it might just look too much just like an ordinary spiral galaxy. I'd like something distinctly recognizable.

Also, you're all going to think this is some kind of Pharyngulian obsession, but I swear my wife and I were talking about getting matching tattoos of octopi before I had any idea who PZ Myers was. The reason is because we knew each other for eight years before we started dating, and so the number eight had some significance in our relationship. I'd still like to do this at some point, but we need to find a design we both like, and also one that is compatible with being in different locations on the body (I want only concealable tattoos for employment reasons, while my wife has no such constraints).

Any suggestions? (Eagle Nebula and M100 images below the fold)