I am not the GP but I learned about C-o by reading the man page. If you spend a lot of time in Bash, why not learn to use it properly? There are less than ~100 key bindings, see "Readline Command Names" in http://linux.die.net/man/1/bash You should at the very least skim over them.

  operate-and-get-next (C-o)
  Accept the current line for execution and fetch the next line relative to the current line from the history for editing. Any argument is ignored.