Hi again, Susan.
I found information on classmates.com for Paul Cooney.
If he graduated from Christian Brothers Academy in 1953, in Albany, NY, you can register for free and send him an email; then, if he responds, you can get Phyllis' email, unless you don't want to involve him, or let him know you're looking for Phyllis' email/cell phone number.
Re: your grandson, you can search on Facebook.com, MySpace.com, Twitter.com, social networking sites where many people have profiles. I don't know if you have to register in order to 'search', but you don't have to use your real name, etc., if you don't want to, and it's free to register. I found two listings for 'Michael DeCrosta' and "Mike DeCrosta" by putting Michael DeCrosta (nothing came up for Michael Vincent DeCrosta), into the search box on Facebook; if you know any of his friend's names, and/or recognize any relatives in the pictures, this might be a good way to find the info you need.
The only other way to find email or cell info, is to go through Intelius or another similar site, and pay to view the info, if they do have it.
Would you please let me know if you are successful? Thanks.