This is definitely stolen from this blog post from Tobias Brink.

Large LaTeX beamer presentations compile slowly, especially if there are a lot of images. While working on the slides, it can help to only compile some of them. In order to avoid commenting them out, you can simply use

\includeonlyframes{current}

in the preamble and mark any frames you want to compile with

\begin{frame}[label=current]
  ...
\end{frame}