Thanks all for the suggestions. Analise, I'll have to check out the two cab companies you mentioned and see what their current rates are to EWR.

I've been aware of the go28 bus to connect to the train, but the Morris & Essex Line only runs once an hour on weekends and other non-peak hours so the timing isn't always convenient.

Another option would be to take a cab from EWR to the Ivy Hill shopping center on Irvington Avenue, which is in the city of Newark but only 1/2 mile (and an easy walk) to my destination in South Orange. Does the fare jump from $18 to $50 once you cross the city line? I'll have to find this out next time I am there.