Why don't my USB drives show up on my Mac OS X desktop ?

Since moving to my new MacBook Pro, with OS X Lion ( shortly to be upgrade to Mountain Lion ), I'd wondered why my USB drives never appear on my desktop, only in Finder.

Well, this evening I decided to investigate further.

A very quick Google search led me to this: -

Q: Perhaps I need to load a driver to get Lion to recognize my WD 500 Password USB drive. However, I thought for sure I could load my thumb drives. But they don't appear anywhere on the desktop (that I can see) when I plug them in.

A: In Finder, click on Finder at the top of the screen, then Preferences. Underneath Show these items on the desktop make sure External Disks is checked. Similarly, click on the Sidebar tab, and tick External disks there. Now close the Preferences window and check your Desktop and Finder sidebar.

Where do mounted volumes and thumb drives show up in OSX Lion?

I checked Finder -> Preferences: -

and, as you can see, I did not have "External disks" checked.

Once I changed it: -

my Lenovo USB3 disk showed up on my desktop: -

Nice :-)