Here are some really useful command line shortcuts that I found on a forum awhile back but don't remember now:
F1 Repeats the letters of the last command line, one by one
F2 Displays a dialog asking user to "enter the char to copy up to" of the last command line
F3 Repeats the last command line
F4 Displays a dialog asking user to "enter the char to delete up to" of the last command line
F5 Goes back one command line
F6 Enters the traditional CTRL+Z (^z)
F7 Displays a menu with the command line history
F8 Cycles back through previous command lines (beginning with most recent)
F9 Displays a dialog asking user to enter a command number, where 0 is for first command line entered