[O] One-keystroke command to move blocks of text up and down

[Susan Cragin]

I use Meta-up-arrow and Meta-down-arrow to move headings in org and entries in 
spreadsheets. 
Would like to be able to use the same or similar command to move blocks of text 
up or down. 
The current solution--highlight then kill/yank--is just too slow.
Suggestions?