This Martini glass was shaped by drawing a vertical half of the glass with splines in the front view and spinning it with the lathe (found in the modifiers tab when the spline is selected). The Mesh Smoother modifier helps to make it look nicer. Ice cubes were then dropped in by using Reactor. Reactor is accessed by right-clicking any grey space on the main bar. The glass and cubes were set to be solid (so they couldn't pass through each other) and the cubes were given some mass. By previewing the animation, the cubes dropped in the glass as they should without the need for manually positioning them. For good measure I made an olive and a toothpick to enhance the image. The glass was then put on a basic table.
Using Mental Ray, some very good glass / liquid effects could be added to the scene. All of these effects were found in the materials panel by clicking 'standard' and navigating to the required texture.