Just like sign language, the sign language alphabet varies from country to country.
The manual alphabet used in Australia is much different from the manual alphabet used in the United States. This means that if you use the ASL alphabet in Australia, they will think you are weird.
I am honestly completely fascinated by the manual alphabets from around the world. They vary greatly. The alphabet used in Australia, Britain, and New Zealand is the same and uses two hands instead of one. I highly recommend learning this alphabet simply for the fun factor.
Some alphabets even use handshapes that are quite difficult to make if you know American Sign Language.
I think learning these different manual alphabets is very useful. When you go to another country, just look for a deaf person, and you can spell out what you are looking for! Just kidding...their alphabet is normally in their native language. So, to fingerspell in Japanese Sign Language, you will need to know Japanese.
Here are some links to the alphabets from different countries:
