Comment Be Up-To-Date, Hide Your Age (Score 3, Interesting) 306
Make sure your skills are up-to-date, and structure your resume in such a way as to not reveal how old you really are. For example, no dates on your education and/or military service, leave off early jobs, etc. You might want to dye your hair if you're gray, although I wouldn't go that far.
It's illegal to not hire you due to your age, but of course it's hard to win an age discrimination suit. So don't let it go there.
Other people have mentioned govt. contracting. Some contracting firms like to hire older techies because they fit in well with the aging population of government workers.