I have a desktop phone, my backpack, my laptop, oversized Thunderbird monitor, keyboard, mouse, notepad, smart phones (personal and work), and my drink. I could easily lose the phone.
I have no pictures up on the cubical walls. My cabinets and drawers are 95% empty.
Even my computer desktop is empty of all but the Macintosh HD icon in the upper right corner plus the menu bar and icon bar.
Everything I use or need are on the computer. I take weekly USB based backups of my personal stuff on my laptop and remove them once they're home. Pithy sayings or odd pictures on the walls are boring after a short time. I've brought things in, pictures, calendars, little miniature figures. But it doesn't take long before I take them home again and put them away (besides the occasional "that's inappropriate" from management for Zombie pictures). Company awards, certifications, training, all eventually get taken home.
Heck, my boss has put pictures up in my cubical (Bill Murray, "Who's Awesome, You're Awesome.") which has come down again in a few weeks.
I've been a contractor or consultant for many years. I'm able to pack up and bail at a moments notice.
I will say that I don't clean the desktop very often although I do clean the monitor (it gathers dust).