Recent Expository Talks
I give numerous expository talks to undergraduate and high school audiences. I have spoken to undergraduate Math Clubs such as Ohio State's Radical Pi for years. This year I began to participate in Math Circles. Here are some recent expository talks.

Sizes of Infinity
Radicalpi Math Club, OSU (2012) 
The Fourth Dimension and Beyond
Columbus Math Circle, OSU (2012) 
Sizes of Infinity (Parts I,II)
Fairfax Math Circle, George Mason University (2011) 
Adventures in Graphs and Electric Circuits
Columbus Math Circle, OSU (2011) 
Whose Curve is it Anyway?: Improv Problem Posing
Radicalpi Math Club, OSU (2011) 
Sizes of Infinity
Science Seminar, Loyola University Maryland (2011) 
Identities with Complex Numbers: Do You ``Have'' to Multiply by the Conjugate?
Mensa Regional Gathering (2010) 
The Real Line is a Proof?
Radicalpi Math Club, OSU (2010)