If you yearn for the classroom environment, then you'll love NetPen. NetPen allows you to use a virtual whiteboard across a network as if you were in a classroom. This is a great program if you just want to have a bit of doodling fun with friends or collaborate on a project across a network.
The tools in NetPen are pretty simple - a pen, a whiteboard, and an eraser. However, there are a few added extras such as a spray can and paint function. The program allows multiple users to connect, so you can have as many people as you want join. Despite this, NetPen doesn't hog bandwidth because it only runs through one port.
Although the color palette in NetPen is limited, it does assist you in drawing various shapes and colors. There are also useful keyboard shortcuts to speed up time, such as the delete key to erase drawings and copy/paste shortcuts. Additionally, a grid can be toggled on and off. NetPen can be set to auto-delete drawings at a set time, which is useful for conducting meetings but not so great if you've just created a work of art.
NetPen is a fun and useful utility for all those who look back with nostalgia at the days when learning was done primarily with a whiteboard and marker pen.