CTRL+1 - move current line up
CTRL+2 - move current line down

Discovered by accident this morning. I've done a quick search, but can't find it mentioned anywhere.

Nifty find, @smithothy !

Actually it transposes positions with the line in that location. Try to move it over an existing line and they swap positions.

Notheless, you have a good eye for experimentation. Gold star for that alone.

Thanks @dw817. You explained it better than I did!
It has already saved me a bit of cutting and pasting.