Everytime I install Ubuntu, my usplash (the boot GUI) is 640x480. So here is howto make the usplash resolution fit your display resolution:

If you want to change your screen resolution, while still running Linux but you are not using Gnome or KDE, which gives good options to change screen resolution, you will have to use the xrandr command

Many People have been having problems with Intel Graphics in widescreen so here is the solution howto fix this.