https://marco.org/2009/01/14/theres-some-speculation-about-what-model-mouse
There’s some speculation about what model mouse David uses (pictured).
It’s the mouse from the Logitech Cordless Desktop S 530 Laser for Mac. (He no longer uses the keyboard from the set.) It’s a nice mouse with a similar shape as the MX Revolution, but smaller and without the cool scroll wheel.