Another one which has been mentioned earlier in this thread is Chester and Chester Road.
A few years back when the works were being carried out at New Street, and as many of three trains were occupying one platform, Network Rail staff were directing passengers for Chester onto our Cross City service for Chester Road. We managed to intervene and get them on the right train, which was just as well given that it was getting late and the prospect of people being stranded was a likelihood.
As a thought, perhaps the possibility of confusion was why Vauxhall and Duddeston (B'ham) is now simply Duddeston.
As for air travel it is not unknown for people to book flights to Sydney and find they have paid for a trip to Sydney, Canada. And I remember that when Ryanair launched flights to Santiago with a £1 (plus tax) promotion, people were miffed to find themselves in Spain, rather than Chile. Mind you, knowing Ryanair's penchant for finding out-of-the-way airports, nowhere near the advertised destination (back in 2006 they advertised flights from Oslo to London (Prestwick)), they probably had intended to grab passengers for Chile.