Accents and dialects and goblety-gook spoken by people.

I just bounced my way over to the "Northern English" page on Wikipedia, and was reminded of the great variety of accents one might come across in their travels through northern England:

Cumbrian
Geordie
Lancashire
Northumbria
Mackem
Pitmatic
Scouse
Tyke

Ahh, such wonderful names for them as well. Go on, check out their Wikipedia pages, and then go an look for examples of people talking in each accent online (for this, though, you are on your own). If you thought that English accents only stretched as far as Cockney, then you've not been to England.

Scotland, too, is also an interesting place for accents, but I'm not going there right now.