We use a barrier cream more than nappy rash cream. We have the Weleda range, which is calendula based. Its lovely! A couple of times we've been out, and I've had a dry patch of skin on my face - and that does the trick cause we only have the nappy bag with us.
The nappy rash cream from weleda works really well - it sort of dries everything out and it heals that way - plus it doesn't do any harm to cloth nappies. Most of the other (zinc based) products will cause a build up in your cloth nappies - particularly on fleece products.