Finally! Thanks to this Palm Pre Shortcuts article I now understand the “keyboard shortcuts” that show in the Edit menu of every WebOS app. They show a bullseye symbol followed by, for example “ C” for copy and “ V” for paste. But I never understood what the bullseye symbol meant. It looked a bit like the onscreen cursor hint that shows when you are in “shift” mode or “orange” (actually white on my phone) mode. But that never worked, and it turns out that the bullseye seem instead to be an attempt to show a glowing gesture area light. You need to hold the gesture area till you get the light and then press the specified key.
I really like the WebOS UI, but it is definitely missing some affordances that let a user know that some functionality exists. I suppose this is a necessary tradeoff in going the Apple route and making the interface radically simple.