John,
Speedometer cables are usually one of the most reliable, necessary components of your car. And for a car that's only a couple years old, that's kinda strange for the cable to simply fail.

You can fix it yourself if you want. There may be some specially tools required for that job, for that particular year of Eclipse. I have never worked on an Eclipse older than a 1998. And the 3G (third generation - 2000 to present) Eclipses are completely different in set up. I couldn't even tell you exactly where I think the cable could be.

I would suggest checking your warranty first. Your car is not old at all, and that part may still be covered. If you can get it fixed free from the dealership, do it. Just don't let them talk you into anything else that may cost money; even if your car needs it.

But if it's not covered under warranty, and you're gung ho in performing the job yourself, find a good repair manual that could assist you; Haynes and Chiltons do a good job.

Sorry I couldn't be more of a help; and good luck!

Anthony