FastRes 

FastRes lets you quickly change your screen's resolution and color depth, from the system tray. It is small, and takes up very little memory.
resolution color depth tray

UIFriend 

UIFriend provides easy and powerful quick resolution changing, intelligent behind-the-scenes protection of your desktop icon layout, a better looking desktop, display setting management for multiple users, and increased screen saver power.
quick resolution changing resolution changing desktop icon layout transparent double buffer display settings screen saver screensaver mute