This is colony PCR (aka Polymerase Chain Reaction). What I'm doing is screening colonies of bacteria for the ones that have the gene I want inside of them. I take a toothpick, dip it in each one of these, and then in some growth medium (pretty much chicken soup).
PCR is a way of amplifying DNA. Whenever they do DNA work on TV (aka CSI) it uses this technique. The guy that invented this technique won the Nobel Prize in 1993.