I don't have an Epic yet (planning on in about a month)....but I'd use the coaster to fill the empty spot from my old phone!!
Of course, I'd also use it all around the house to watch shows, have it on my nightstand for a nice clock display, take it with me to watch stuff on the phone when I'm sitting waiting somewhere, etc!!
I would use this at work and home to use my phone as a portable picture frame and have a slideshow of my daughter. Yes, I'm playing a little bit of a sob story, but I don't get to see her as often as I like and this way it feels like she keeps me company.
I can use this as I sit in the bar at night, eating and enjoying a few adult beverages (salesman). Oh yah, at the beach to keep the Vibrant out of the sand. It hates having sand in its "cracks".
I would use this in my Touareg because I use my phone as my GPS, Music album and voice text, and right now, my Galaxy S it keeps falling in the floor due to lack of a holder.
I would use the smartphone coaster with my droid x on my night table in the bedroom, my desk at work, the dashboard in my car, the sink in the bathroom, it would be my constant companion!