configuring gdb (gud) to start on a given file

[Dan Hitt]

When i start gdb the first time in an emacs session, it prompts
   Run gdb (like this): gdb  

After running it once, it remembers what the previous executable.

How can i get the gdb (gud) mode to either remember between
emacs sessions, or set a default executable and/or gdb command
in my .emacs file?

I'm running 21.2.1, as distributed in Mac OSX, 10.3.2.

Thanks in advance for any info, including pointers to info
pages or man pages or FAQs.

dan