I've probably already posted this picture a long time ago, it's of a black phase long nose butterfly. While long nose butterflyfish are found in most of the indo-pacific, Hawaii has two species, one of which is endemic (lives here only) and has a longer nose. Occasionally you will see a black phase, which is considered very rare, in Hawaii, mostly in Kona. We do have spots where you can see several of them on a single dive.
Back to the topic of the title... gettting around in Kona: I've always recommended getting a rental car when you come here, but there are many people who do want other options, so I'll discuss them here. First thing one needs to know when coming to Kona is - there is no walking to anywhere from the airport. I had someone asking me how long of a walk is it to the Fairmont Orchid from the Aloha terminal last week, and while I'm not exactly sure, it's something in the range of 27-34 miles or so (a longer distance than most people want to roll their luggage). The Kona airport is roughly 6-7 miles from anywhere, out in the middle of a 200 some odd year old lava field. Kailua is 6 miles away to the south, the nearest resort is roughly 7 miles to the north, and most are quite a bit further.
The second thing you should know is, there is essentially no public transportation system as known on the mainland. While there is a bus that circles the island daily, and a bus that services part of Kailua and south Kona a couple times daily, there is no readily available bus system to hop onto.
That basically leaves you with two other options for getting to your hotel (the hotels here don't have specific shuttles, but I suspect if you throw enough $$ their way they might arrange for private transportation) when coming to Kona and determined not to rent a car - Taxis and Speedishuttle. Just a note, in many cases, a day's car rental will be less than a taxi or shuttle ride. Taxis are readily available at the airport upon arrival, and if you are wanting to get somewhere immediately, this may be the quickest method. Speedishuttle is a company I didn't even know existed until 3 weeks ago when I decided to pick up a part time evening job, apparently they've been operating here for years with 4 or so shuttles servicing the west side so they weren't highly visible, but they are increasing their fleet size so you see more of them at the airport now.... OK, gotta tell you, I'm working for them now as a greeter at the airport a few evenings a week, so I guess this is a plug for my employer, but they are a legitimate option for getting around. Anyway, the shuttle does service all the major resorts, is usually a bit cheaper than the taxis generally and can carry a bunch of luggage without a per piece charge. One hint though, see if there's a greeter for them outside the luggage carousel when you arrive and arrange for the shuttle before you wait for your luggage - you will wait for your luggage in Kona, as this is a small airport and you can walk to the carousel in roughly 60 seconds - that way a shuttle is very likely to be waiting or on it's way when you do get your luggage. Shuttle service is generally not a long multi-stop thing here as it is in bigger tourist areas, it's still sort of a fledgeling industry here in comparison to Orlando or Vegas or major cities, you very well may have the shuttle to yourself or one to two other groups from what I've seen. Both taxis and shuttles are not inexpensive, as there's generally a fair amount of distance to be covered to get anywhere from the airport, but they can be handy for someone who wants to stick to the resort areas or Kailua.
If you do get a rental car, don't be overly concerned about getting lost. I get questioned about how difficult it is to find your way around Kona on occasion. Kona essentially has only one north/south highway and Kailua has maybe 2-3 north/south streets with a limited number of cross streets. It's small. There were only 6 or so stop lights on the entire west side of the island when I moved here just 8 years ago, and now maybe up in the teens... it's not an elaborate road system.
I hope this helps some. For those wanting specific locations check out the online mapping services, and then keep in mind they arent' necessarily accurate or complete, Mapquest used to be about a mile off on our street address, showing a completely different subdivision.