For almost 14 years, there has been a justice on the U.S. Supreme Court who used to chair the U.S. Equal Employment Opportunity Commission (EEOC). While heading the EEOC he held up some 20,000 age-discrimination complaints until the statute of limitations for filing lawsuits expired.
Yet there are ways to hide your age until you actually sign-on as an employee. Never discuss any part of your career that ended more than 10 years ago. Touch up your gray hair; Clairol (or some other brand) is your friend. Men should touch up their mustaches and beards, too. (But DO NOT resort to comb-overs, toupees, or other ways to hide your baldness.) You can readily claim your college degrees, but do not mention when you earned them.
Another area for caution is your salary history. Avoid discussing this. Take the position that you prefer to consider total compensation, including fringe benefits. Also indicate that past compensation might have been earned for an effort different from the one you are being considered. If you need the job and are willing to work for less than you used to make, do not allow your prospective employer use your past salary to disqualify you.
Also, remember that old dogs do indeed learn new tricks. If you are experienced in three computer languages and three operating systems, the next one will be very easy to learn. In any case, the old tricks are sometimes very valuable.
See my http://www.rossde.com/unemploy.... This might be somewhat dated, but the overall content could prove useful.