I'd suggest multicol package
Note that if you use screenplay, you need to redefine some lengths iniside multicols, for example
\begin{multicols}{2}
% REDEFINITIONS
\setlength{\dialwidth}{2.0in}
\setlength{\dialgutter}{0.1in}
\renewcommand*{\dialtab}{\hspace*{0.1in}}
\begin{dialogue}{Bob}
That means that someone
sabotaged the unit and killed the
President! Was it one of us?
\end{dialogue}
\begin{dialogue}{Brown}
Who else is mad but us, Condi\ldots
\paren{beat}
and Bliar?
\end{dialogue}
Bob buries his head in his hands.
\intslug{Atlantis -- somewhere ANyway}
JOHN and MARK are at adjacent consoles. FRED is with them. TOM
is at another console slightly further away.
\begin{dialogue}{John}
The planetoid seems to have a thin crust
covering a nickel-iron core. Could have
been an Earth-like planet at one time.
\end{dialogue}
\begin{dialogue}{Mark}
We're coming up on the radio source now.
\end{dialogue}
Brown walks in and goes to a console.
He has a PARROT on his shoulder.
The Parrot has an air of quiet insouciance.
\end{multicols}
etc...