Here's a follow-up to my previous comment...
I was looking for a way to make the parent column an autocomplete field (using SPServices.SPAutocomplete). My workaround was to let the parent field remain a dropdown lookup, but I wrote a couple lines of jQuery which modifies this the selected option of this parent dropdown with the text of whatever was chosen from the autocomplete field. I then made the parent dropdown invisible with some CSS and viola! Seems to work well.
↧