Elizabeth, I am a hobbyist and not an expert. I have done some research regarding my own ancestors, who were Marine Corps and Army infantry vets. Based on that experience I would make the observation that your best chance of finding "some who remembers your dad" will probably be through a veteran's organization, such as a vet association, or ship reunion group.
I poked around the Internet a little bit, searching the usual haunts, and found these pages that should be of interest to you:
You will notice there (among other things) links to a, "Tin Can Sailors Website". At that site, you will find further links to info more specific to the ships you referenced: the Howard and the Lang. One in particular is this:
It is the page which shows current ship reunion info for destroyers whose names start with "S". You will find there a listing for the Lang, with a reunion of the ship's company scheduled for August, 2008 in San Diego.
Also at the Tin Can Sailors Website you will find this link with contact info for vets of the Lang (it is found through the "Shipmate Registry" link: