That's a very cool patch. When my father was an assistant chief for the fire department here, the Secret Service would keep all of their vehicles overnight at the fire department headquarters. It was really cool, because they'll show the vehicles off. Usually they would give out some cool stuff too, I have a bunch of Secret Service challenge coins and I believe a regular Secret Service patch.
Despite their appearance of being hardasses, Secret Service agents are mostly really nice people just like you and me. I got to know quite a bit of Hillary's and Obama's agents during the 2008 campaign season when I was working with a photojournalist. Most of the agents that traveled with Obama back then are still assigned to him today.