In my experience, lockers at airports are fairly common. Equivalent / synonymous services are termed baggage storage or left luggage. Service can be self-serve or requires interaction with people.
You can almost always check online before you get to an airport. Most airports have a website, and even if woefully lacking in design, colour and possibly an English translation, will hopefully be able to tell you if there is a service where you can store your bags, or if there are lockers available. As you would guess, they usually cater for people with a long transit (so searching for services for transit pax is an idea).
I think all the major airports in Australia have luggage storage services, with the possible exception of Canberra (read: I have no idea). Brisbane and Perth have self-serve lockers (the former in the International terminal car park and the latter in the Domestic terminal car park), Darwin has serviced lockers (i.e. a security guard will "help" you), and the others are through a serviced counter.
A possible alternative if an airport doesn't have a storage service is to see if lockers or a storage service is available at a train or bus station which is along your journey to and/or from the airport. For example, a decent number of the
Hauptbahnhof (main (train) stations) in Germany have lockers, which also connect by train to the airports. These may turn out cheaper than the airport storage service, albeit you will have to drag your bag away from the airport.
The next thing you might be able to do is try and check in before you leave the airport. This puts your bag into airside and you don't have to worry about it. Problems with this are:
- Many airlines will not let you check in more than 3 hours before departure. This is even more so if the airport is not one of the airline's major hubs, and/or you have no elite status.
- There is a chance you can be viewed as a security threat if you are 'caught' checking in a bag and then leaving the airport. Technically no one can stop you, it's not really illegal, but for legal reasons the airports and airlines don't like it.
Hiring a car is expensive, but if you want to travel around like this then it solves your luggage lugging problems, too.
Unfortunately if there is no option from the above, you might just be stuck lugging your bag around the place!
In short, there really is no secret, except perhaps it pays to do some homework. If you had some specific locations in mind, some of us who have been there might be able to help you out.
P.S. A little bit of Googling showed this service which exists near LAX. They also do pick-up and drop-off:
LAX Luggage Storage.com Not precisely cheap nor convenient, but it
is a way of storing luggage at LAX......
