An application script that opens files in iTerm's vim

gistfile1.applescript

on run {input, parameters}
	if (count of input) > 0 then
		tell application "System Events"
			set runs to false
			try
				set p to application process "iTerm"
				set runs to true
			end try
		end tell
		tell application "iTerm"
			activate
			if (count of terminals) = 0 then
				set t to (make new terminal)
			else
				set t to current terminal
			end if
			tell t
				tell (make new session at the end of sessions)
					exec command ("vim \"" & POSIX path of first item of input as text) & "\""
				end tell
				if not runs then
					terminate first session
				end if
			end tell
		end tell
	end if
end run

Create an application through AppleScript Editor, then set 'Open with' for all extensions to use your application.