copy-something-to-mark.
Put a mark in your destination, then move point onto the "thing" you want to copy, pick up a function, which I used to bind to some key-bindings, the "thing" will be copied and pasted to the mark automatically.  You don't ever need to select something very carefully by your mouse, and then type Meta-w and Ctrl-y

Supported "thing" including word, line, paragraph, string and things enclosed in parenthesis.  

In some special condition, such as in shell-mode and eshell-mode, "thing" will be automatically copied to the prompt line. Not necessarily to set mark explicitly.