Some talks and presentations, in reverse chronological order (don’t be surprised to find repeated material/slides as the topics do overlap):

IPython & StarCluster: Scalable Cloud Computing for the rest of us(a Qiime illustration)

Short slides introducing a demo presented at the NIH cloud workshop.
IPython: Python at your fingertips
Talk delivered at the PyCon 2012 conference in Santa Clara, CA. It combines a rapid overview of the IPython project with hands-on demos using the new HTML notebook interface. This is the full video:
Ten years of (interactive) scientific Python
August 2011, the slides for my keynote presentation at EuroSciPy (I don’t have video available). Many thanks to the awesome organizing team, in particular Gaël Varoquaux and Emanuelle Gouillart for the invitation, hospitality, and amazing work they’ve done with EuroSciPy and Scientific Python in general.
Python: a view from the floating-point side

March 2011, a talk presented at the Sage Days 29 workshop, on the use of python for numerical work, with some historical personal background.

William Stein recorded the talk and posted it online, as well as posting some pictures from the last day (for those who have asked, the anecdote about how I unplugged Colombia from the internet when I was a physics undergrad is from 0:11:20 to 0:14:12):

Reproducible software vs. reproducible research
February 2011, a talk presented at the panel titled The Digitization of Science: Reproducibility and Interdisciplinary Knowledge Transfer, during the 2011 annual meeting of the AAAS. An extended abstract is available that spells out some of the ideas I presented in the talk; I hope to complete this writeup into something a little more formal soon.
IPython: beyond the simple shell
December 2010, invited talk at the SciPy India 2010 conference. A longer overview of the IPython project, from its start to the recent developments.
IPython: a quick overview
October 2010, short summary of the state of the IPython project.
Python: performance and parallelism
November 2010, guest lecture delivered for UC Berkeley’s CSE: Science Research Computing with Python (CCN 06180) graduate course.
The state of IPython
August 2009, a short update on the project, delivered as a lightning talk at the SciPy‘09 conference.
Data Arrays: Name that axis!
August 2009, a short talk about an idea I am working on, to add named axis support to NumPy nd-arrays (another SciPy‘09 lightning talk). The code for this project is available on github.
Python and parallel computing: an overview
April 2009, delivered at the UC Berkeley ParLab.
Python & Scientific Computing: Leading the charge for open source, high-level tools
November 2008, presented at the Bay Area Python Interest Group meeting held at Google’s Mountain View campus.
An overview of Python’s role in scientific computing today
July 2008, presented at the annual SIAM meeting in San Diego (see my blog for details on our minisymposium there).
Some reflections on modern algorithms research
October 2007, NSF headquarters, CDI program launch meeting, Washington DC.
Python for scientific computing, an introductory overview
August 2007, NCAR (National Center for Atmospheric Research), Boulder, CO.
Physics, mathematics and computers (Better algorithms + better tools: better science)
May 2007, University of California, Berkeley.
Physics, algorithms and computers (A short tour of a few things I’ve done)
April 2007, TL, Chicago.
Adaptive application of Green’s functions (Fast algorithms for integral transforms)
April 2007, University of Michigan at Ann Arbor.
IPython: getting the most out of working interactively in Python
February 2007, PyCon‘07, Addison, Texas (talk presented by my colleague and friend Brian Granger).
Multiwavelets, gaussians and Green’s functions: a new kind of fast algorithms for PDEs
September 2006, Colorado State University, Fort Collins.
Python for scientific algorithm development
August 2006, SciPy‘06, Caltech, Pasadena, CA.
Multiwavelets, Gaussians and Green’s functions
April 2006, SANUM‘06, University of Stellenbosch, Stellenbosch, South Africa.
Interactive scientific computing environments
February 2006, Sage Days, University of California, San Diego.
Python in scientific computing (an illustration with multiwavelets for PDEs)
November 2004, Colorado School of Mines, Golden.
Green’s functions in many dimensions and multiwavelets (Python for a new class of fast algorithms)
September 2004, SciPy‘04, Caltech, Pasadena, CA.
Interactive work in Python (IPython’s present and future)
September 2004, SciPy‘04, Caltech, Pasadena, CA.
IPython: an enhanced interactive Python
September 2003, SciPy‘03, Caltech, Pasadena, CA.
Instanton correlations in the finite temperature QCD vacuum
November 2002, University of Colorado, Boulder.
Speeding up Python with C/C++
April 2002, Front Range Python Users Group, Boulder, CO.
Particles, fields and computers: the building blocks of nature and their numerical study
December 2000, Colorado College, Colorado Springs.
Instanton molecules in finite temperature QCD?
April 2000, University of Colorado, Boulder.
A semi-classical approach for Lyapunov exponents of a quantum mechanical system
June 1998, University of Colorado, Boulder.