Use CTRL-R " when entering a command in command mode to paste the current paste buffer contents. Substitute " for a buffer name, % for current filename, / for last search term, + for the X clipboard or a host of other substitutions.
CTRL-R also works in insert mode, no more skipping back to normal mode to paste!
Check out the vim documentation for CTRL-R -http://vimdoc.sourceforge.net/htmldoc/insert.html#i_CTRL-R