Document Classes ⇒ [beamer] Add additional information to title page

[deus]

Is there a way to add additional fields to the title page in a latex beamer presentation? By default, you have title/author/etc, but I would like to add a field 'supervisors' where I can specify the names of my supervisors.

[mregine]

The way I do this is to add them into one of the existing fields, e.g.
\author{M.Y. Self\\[2\baselineskip]
Supervisors: So and So}

You'll have to fiddle with spacing to get what you want.

As for positioning, you could specify the layout of the titlepage by hand, adjusting spacing as you see fit with \inserttitle, \insertauthor, ..., \vspace, \vfill..., or completely redefine \titlepage yourself.