On Twitter, I'm at @mattphillion, and Entropy Emily has her own account (madness, I know) @entropyemily.
I'm kind of a Facebook junkie, where you can reach me on The Indestructibles page, https://www.facebook.com/whoisindestructible. I've also just launched an author page, https://www.facebook.com/matthewphillion. There's not much there yet, but that page will be expanding a bit in the future.
Lastly, you can always reach me here through the contact us button at the top of the page.
Hope to hear from you!