To move a browser window to a specific location on the users screen:
window.moveTo(x,y);
replacing "x,y" with pixel coordinates.
More info here, where they also have the below which will give you the users screen width, height:
screen.width
screen.height
Also, to resize the browser window:
window.resize(width,height)
Now, before you go all crazy on me – I'm not suggesting people do this for sport on their blogs. Messing around with people's browser's sizes, position, etc. will be annoying and NOT very usable. The reason why I needed the code above was to create a "minimize my browser" type effect with a bookmarklet for my mac (aka. "hide! the boss is coming"). The end result is this: mini-me