Please use all of the standard text editing shortcuts.
MacOS X, by default, uses a lot of the "Emacs Style" key bindings.
ctrl+e : end of line
ctrl+a : beginning of line
ctrl+d : delete 1 character forward
ctrl+k : kill line (basically deletes it and puts it in the yank ring)
ctrl+y : yank, pastes the line that was 'killed' with ctrl+k (basically provides a second system wide copy and paste buffer).