Hating to deal with the inconvenience of the ZoneEdit "only the first five domains are free" rule (yes I’m very cheap), I searched for a free alternative and I think I found it, XName. Though the ZoneEdit user interface is simpler and probably more helpful, making it more suitable for beginners, XName does not lack in features and the interface is arguably more convenient once you get used to it.
In any case, its really a great and free service, so please contribute some spare cash if you use the service and can afford it.