- It's faster going to a webpage if a browser window is already open.
- Most webpages use memory and processor time redrawing and refreshing, even when in the background.
So what can you do? Type "about:blank" in the location bar of Firefox or Safari and hit return. Ta-da! Blank page!
In Firefox, you can blank your screen with two keystrokes. Go to "Organize bookmarks", create a new bookmark with "about:blank" as the location, and set "b" as the keyword. Now to blank your screen, simply type cmd-L to go to the location bar, then "b" and "return". I guess that's three keystrokes, isn't it?
Still, a nice way to leave the browser ready to go without it occupying resources in the meantime.