Run program in adjustable window

[JBot]

Im wondering if there is a way to run a full screen app inside a resizable window, so that i can see more than just that one program.
Scenario: I want to be able to play a video game, but im at work and have others things i have to watch at the same time. Lets say for this scenario my job is a video game tester. When i play the video game now, it just fills the screen and the only way to see the desktop again is by closing the game.
Is there a way to do such a thing?

 

[M@lew]

Depends what program. If you can do this with a program/game, it'd usually have the option within a menu inside the program.