Editted for the RunCore drive, removed information about the defunct Generic
SSD this article was originally about.

And a video,
on YouTube.
How I figured this out.. The STEC
SSD uses a controller that is BGA, meaning all of it's pins are underneath it. But the RunCore
SSD has a controller with all of it's pins accessible. So that's what started my gears moving. I started with getting the tech sheet for the controller on the RunCore
SSD. It is a JMicron JM20330. That got me the pinout of that controller. I knew that if you tapped a certain wire on a standard PATA ide cable, you could use that wire to drive an activity LED. I did some googling and determined that it was pin 39 out of 40. Some more googling and I found that the name for that wire is "DASP". Looking at the pinout for the controller on the RunCore
SSD, it was pin # 42 on the controller. That pin is the 2nd pin in from one of the corners. I wasn't looking forward to soldering to that leg, that far in. Luckily, I noticed a trace leading directly away from that leg. I followed it to a resistor. I used a Meter to confirm that's where it lead, since there was some silkscreened writing on top of the trace obscuring it. Once I confirmed that it was going to that resistor, I simply soldered to that side of the resistor. MUCH easier to solder to. I tried my best to take a picture of which resistor you are soldering to, I think it's pretty clear from the picture. It's normally under a sticker that you'll have to peal back. Please do not do this if you don't think you are a soldering wizard. And be aware, this WILL void your warranty. Say goodbye to that warranty.

Next, I needed some power. Being an LED, 3.3v is plenty. So I googled up the pinout for the MiniPCI-e slots, and saw that 3.3v was available at pin52, among other places. So I ran a wire from the unpopulated MiniPCI-e slot's pin 52.

Next, I quickly put the machine back together to do a quick trial on my desk to see if my research had been correct and this really would get me an HDD light.

Bingo! It works. Just for the record, I used a 3mm LED, 1k resistor (far more than I needed, but very safe, and you have to go a lot farther overboard on resistance before the LED starts getting dimmer)
Now I went and downloaded the disassembly guide from Dell and took the machine all the way apart. I found that I could tuck the LED right up next to spot where the lights come out the front of the unit. Unfortunately, I didn't snap any pictures of the LED installed. I used some superglue to hold the LED in place. If you go to do this after me, this step should make itself pretty well obvious. I used heatshrink tubing to protect the bare leads at the LED.
So that's about all there is to it. The hard part really was the research. Check out the video I linked at the beginning to see the light in action.
And before anyone asks.. I know someone is bound to.. No, this will not even SLIGHTLY affect your battery life. The LED draws 20ma at most, and is on a very small portion of the time the machine itself is on.
And one other note.. I did not disable the low battery LED. It'll still blink orange when the battery gets below 10% like it always has. When the low battery light is flashing while the hard drive is accessing, you get a kind of pinkish color.
Final note, again, this article was edited from the original post regarding the now discontinued "Generic MLC
SSD's".. I kept most of the wording the same and just changed the names and some of the facts. I liked the way I had written it last time.

If you don't want to void your warranty, there are
some software solutions.