Full screen (Save to Desktop) – CMD+Shift+3
Full screen (Save to Clipboard) – CMD+CTRL+Shift+3
Select region (Save to Desktop) – CMD+Shift+4
Select region (Save to Clipboard) – CMD+CTRL+Shift+4
Select item (Save to Desktop) – CMD+Shift+4 then Spacebar
Select item (Save to Clipboard) – CMD+CTRL+Shift+4 then Spacebar