An old Navy buddy of mine told me about a great website called Together We Served. www.togetherweserved.com/
Go to the home page (Link above) and there you will find links to pages for the US Navy, US Marine Corps, US Army and US Air Force. It is free to join, then you can set up your profile with your rank, awards, certificates and lots of other stuff. Then you can start looking for old friends. It's a great site and I have already connected with several old friends who I haven't talked to in 15 or 20 years.
Check it out.