In both the Windows and Mac versions of Rhino you can customize the pop-up menu that appears when you click on the middle mouse button. You’ll see me do this often when I’m working in Rhino – it’s a huge productivity booster.
To customize in Windows:
Click the middle mouse button
click on the small gray bar at the top of the menu – this will “dock” the menu
remove items from the menu by holding shift as you drag them off the menu and into the workspace
add items by holding CTRL as you drag from an existing toolbar into the menu
To customize on the Mac: