I actually find that I write lots of songs while at a con. Part of it is being in an environment where there's lots of music around and I can find an hour or so to hide out in my hotel room when the inspiration strikes.

Off the top of my head, Nobody Calls, Wandering, Look At Me, Power, The Colors of You, You Are My Life, Butterfly Wind, Hyperspatial Network, Dance by Starlight, One Last Dance, Dinner Party, Too Many Years, Half a Chance, Shades of Gray, and Winter Waltz. (Ok, I just cheated and looked up titles on the website.)

Dream Ship and Good God, Almighty were written in the car on the way to a con, which can be even more challenging. :)