Navigation Devices
Collection of assorted stuff...
Not all mice are created equal...
Multi-button Mice
While SketchUp is designed to work with a standard 2-button mouse, modeling efficiency and speed could be greatly enhanced by adding favorite keyboard shortcuts to the mouse.
Logitech MX Master 3 This mouse has a cordless laser engine with 'programmable' buttons. In other words, you can assign several keyboard shortcuts to the mouse - such as Undo and Redo to the Forward and Back thumb buttons, and there are 4 programmable gesture buttons under the thumb for keyboard shortcuts. Requires Logitech Options software.
Logitech G604 Wireless gaming mouse with 15 programmable buttons total, but actually, there are 10 available buttons to assign one's favorite keyboard shortcuts. Other multiple button mice are out there too. Requires Logitech G Hub software.
Other navigators
3Dconnexion has several navigators for the left hand. It lets you pan, orbit, and zoom with one hand while using another SketchUp tool with a three-button mouse. SketchUp School has a video demonstrating some uses of the Space Navigator.
FPS Nav Alan Chatham - First Person Shooter Navigation. Use arrow keys, WASD, and Numpad to navigate.
CadRemote Maide - iPhone / iPad app which will act as a navigator for SketchUp on Mac and Windows.
Maide Control 3D control input device on an iPad for SketchUp installed on either Windows or Mac - something like the 3Dconnexion navigators.
Pinnacle Game Profiler Joystick control option. Profile for SketchUp 2013 needs some adjusting for more recent versions of SketchUp, but reportedly this device works with Windows 10. The controller driver needs to be installed too.
Remotix VNC remote access tool for iPhone and iPad to touch/control your SketchUp model on Mac, Windows, and Linux.
Wiimote Used for presentation - Alex Schreyer
Presentation plugins and programs listed on the SketchUp Sage Resources page
Mac Stuff
ControllerMate Remap HID devices, like keyboard and mouse buttons.
FlyGesture Customize a Mac mouse to select SketchUp commands with mouse gestures.
Middle button click "hack" Program to add extra function to the Magic Mouse. - Snow Leopard and possibly Leopard
Navigating Sketchup with a MacBook Pro Eric Schimel
PowerMate USB Assignable controller, a special knob to place keyboard shortcuts.
Remap apps
AutoHotKey Remaps keyboard and mouse keys.
xpadder Reconfigures a gamepad.
GlovePIE Reconfigures joysticks, gamepad, 3Dconnexion navigators, Wiimotes, etc. to work in many programs. A SketchUp Group post by Patrick on what he accomplished with this app.
KeyPad+ Map virtual keyboard on iPhone/iPad/iPod. KeyPad for SketchUp, Fee - Windows, Mac