I just read an article in the 10/22 edition of Business Week on the above topic and am curious as to what companies besides those mentioned in the article (Home Depot, Bertelsmann, EarthLink , TIAA-Cref and Jones Apparel Group) currently offer health care advocates? Whether or not anyone has been able to take advantage of them in conjuncton with their HDHP/HSA plan? And what their experiences have been?

Healthcare advocates are intermediaries offered by employers to figure out insurance statements, cut through red tape to get proceedures covered, NEGOTIATE FEES, provide elder care guidance, and basically serve as the employee's advocate for anything they need relative to their health plan. Sounds like a great option, but wonder how wide spread these things are.
http://www.businessweek.com/magazine/content/07_43/b4055089.htm

I've never worked for a company that offers one of these, but I've read about them and the response always seems to be overwhelmingly positive.

Relatedly, most major insurance carriers offer free access to a 24 hour toll free Nurse service. I've used this before, and it's a great resource -- especially with an HSA, when more of your personal money is on the line. For example, a few months back I was having serious acid reflux problems -- much worse than I had ever experience before. I was strongly considering a trip to my doctor to get checked out, but it occurred to me to try the free nurseline first. I made the call, got right through to a nurse, and she helped me recall changes to my diet that were causing the problem. She also encouraged me to try some new over-the-counter options, give it a few days, and then see the doctor if the problem persisted. And ultimately, the OTC drug and changing my diet did the trick in the matter of two days, and I saved $100 by not going to the doctor.

So I'd definitely say that -- in my experience -- having an informed third party can really help in making better (and cost-saving) decisions.

I think the only problem with these Free Nurseline services is the fact that most people don't even realize they have them -- I had to dig through my insurance enrollment information to find out I had it. I'd recommend everyone look closely at their insurance info or insurance carrier's website -- you probably have it and don't even realize it!