Where can I stay besides hostels?

I would also say that hostels are the cheapest. Other than that you can consider rental apartments and guest houses. You will find different type of atmospheres in various hostels, gust houses or apartments. I feel that if the accommodation is clean and well located then one shouldn't have any problem. While selecting accommodation the main thing you must consider is that it should be conveniently located and well served by local restaurants and transportation modes. Otherwise the transit costs can rise.

Thanks. I will give hostels a shot.

But also, how about this idea for when I go to Australia: I rent a car for $40/day (which is about the cost of a hostel) and sleep in it? I'll still do the hostels but it might be fun to sleep in a car, shower at a public shower like at the beach or something.

Speaking as someone who has actually lived and slept in a car, unless by car you mean combi, SUV, camper or some other vehicle large enough to house a bed, I will tell you with no hesitation that it is NOT fun. Plus you'll need to pay for the public showers and you run the risk of arrest or worse if you're not in a campground of some sort or on private property (that you have permission to be on). Sorry but honestly that's one of the dumbest ideas I've ever heard...

My trip will be filled with dumb ideas. I have the most fun with my friends doing dumb things.

Haven't done the car thing in over 45 years but still dread the thought of it!

Having spent fifteen months doing the hostel/guesthouse/campervan/couchsurf combo with eight kids and a grandpa in tow, I'll say each has its place. Cannot comment on hotels as we didn't stay in any.

Personally I love the idea of pulling a gygpsy caravan around the world, so I'm a bit crazy like that;-)