maxframe provides the ability to maximize the emacs frame and stay within the display resolution.
Example of lines to be added to your .emacs:
(require 'maxframe)
(add-hook 'window-setup-hook 'maximize-frame t)
If using two framebuffers (monitors), it might be necesssary to specify a mf-max-width value set to the pixel width of main framebuffer. This is necessary because emacs does not yet support sniffing different framebuffers. Example:
(require 'maxframe)
(setq mf-max-width 1600) ;; Pixel width of main monitor.
(add-hook 'window-setup-hook 'maximize-frame t)
To restore the frame to it's original dimensions, call restore-frame:
M-x restore-frame
puts the emacs frame in the top left corner of the display and calculates the maximum number of columns and rows that can fit in the display
Requires Emacs 22 (for fringe support), but maximize-frame still works under Emacs 21 on Windows.
Emacs does not recognize when the display's resolution is changed. This is a problem because I would like to be able to re-maximize the frame after connecting to a display with different resolution. Unfortunately, display-pixel-width and display-pixel-height yield the display resolution values from when emacs was started instead of the current display values. Perhaps there's a way to have emacs re-sniff these values, but I'm not yet sure how.
The w32 specific functions were borrowed from the Emacs Manual: http://www.gnu.org/software/emacs/windows/big.html#windows-like-window-ops