I don\'t find the oft-used \"*\" to be very nice looking - can anyone suggest a nicer-looking method or point me to an example?
I tried making the field highlighted
Sometimes it really is justifiable to mark fields as mandatory and optional. However, before you do so, you should question whether it is reasonable to ask the user any non-mandatory information. This applies especially in registration forms.
In registration forms and such, it is much better to ask only the minimum information. After the registration the user can, at will, fill out optional information in separate forms.
After all the unnecessary cruft has been taken out from the form, you might see that there is no need to mark fields as mandatory; either everything is mandatory, or it might be so obvious to the user which fields are optional, that there would be no need to give visual cues about it.