By popular demand, here is a series of frames showing the E144 laser
colliding with a beam electron and producing an electron-positron
pair: (note: clicking on image will make it display in a window by
itself; clicking "reload" will then make it look better on many
browsers)
A possible caption: This sequence of images depicts a 46.6
billion volt electron from the Stanford Linear Accelerator (blue)
interacting with an intense pulse of light from the University of
Rochester Table Top Terawatt laser (drawn in red, yellow, and white to
indicate intensity). The electron emits a photon (green), which is
then converted into matter: an electron and its oppositely-charged
counterpart, known as a positron.
And here is the same thing without the particles (for those who
want to draw them in themselves):