I love public speaking, and am often available for short talks that are both fun and informative. My main topics are the science/arts overlap, and the culture of science. You can see some examples of my talks here.
In my talks for non-scientists I usually assume some familiarity with music, art and literature, and use that as a vehicle for talking about scientists and science. For scientists, I mostly speak about culture changes around publishing or career development.
(Photo above by Steve Cross)