If you are running Ubuntu under Parallels on a Mac, you can increase the screen resolution past the default of 1024x768 if you like. Here's how:

1 - With Ubuntu running under Parallels, open a terminal window. I assume anyone running Ubuntu know how to do that, but if not go to Applications -> Accessories -> Terminal.

2 - Type in the following: sudo dpkg-reconfigure -phigh xserver-xorg and enter your root password when prompted.

3 - Scroll up or down (as needed) to highlight the vesa option and press Enter.

4 - You'll see a list of screen resolutions. You can use the arrow keys to scroll through the list and press the space bar to select/deselect until you the resolutions you want to use are all selected.

5 - Once done, restart the X windows session by typing Ctrl + Alt + Delete.

6 - When it restarts, you should get a dialog window that allows you to select from the list of resolutions that you enabled.