If you’re rocking a large monitor and want to take advantage of all that space when you’re reading and replying to emails, head over to Gmail Labs to turn on the Preview Pane.
You can split the screen vertically or horizontally–vertically seems like the best bet since most new large monitors are widescreen format. On the left hand side you’ll see your emails in list form with a brief preview of the initial text and in the right side you’ll see a regular editing window. Essentially you’re able to look at you inbox/tags/search results while also composing emails. Hit up the link below to read more about the features in the official Gmail announcement.
New in Labs: Preview Pane [The Official Gmail Blog]