mDesktop is a lightweight application that allows the user to utilize multiple virtual desktops.
Holding Alt+Desktop Index (e.g. Alt+1, Alt+2...) switches between desktops.
Keystroke Alt+Ctrl+Desktop Index sends the active window to selected desktop (e.g. Alt+Ctrl+2 sends active window to the second virtual desktop).
Right Clicking on tray icon and selecting "Hide Icon" hides the mDesktop tray icon while the application is still running, allowing you to have a "boss" workspace.
mDesktop has a 300-400KB memory footprint, making it the most lightweight option out there!