A few years ago, there was a web design company in town named Naked-something, (we can't remember what it was called!!) And we found this out because they were immediately after Nakagawa in the Nelson phone book, and yeah, we got a few calls. I didn't like this because from the name of the company alone, you couldn't tell it was a ... legit business, and some of the calls were, shall we say, iffy. They've changed their name since.
So yesterday, walking though the Information Centre car park, guess what I saw? I don't know if these folks are based in Nelson, but it was icy cold yesterday and I couldn't help laughing.
There are a lot of privately-owned shuttle bus companies traveling to/from Picton (where the ferry from the North Island arrives), Blenheim, Christchurch on the East Coast, and some, I think, to Murchison and the possibly the West Coast. (It's been a while since I worked in the travel industry). The comfort level of the shuttles depend on the vehicle and the exact seat you sit upon, but the fares tend to be cheaper than the bigger bus, and are popular among young people and locals.
If you need to be dropped off, for example, at someone's farm gate on the main road, shuttle drivers can be very accommodating.