HHGTTG means Hitchhiker's Guide to the Galaxy
The Dutch version of this trilogy in five parts of Douglas Adams is called: the Galactic Hitchhiker's Manual. It is a comic science fiction story that began as a radio radio play in 12 volumes, which aired in 1978 by the BBC. In the early ' 80, a television series was released and in 2005 a film adaptation came out. The story is well known and loved by nerds and geek world wide. Known cries are the fact that you always have to have a towel when you are on the lifts (May 25th is known as International Towel Day). Another known phenomenon is ' 42 ' which is the answer to every question, and also comes back in other films that refer to it.
Hitchhiker's Guide To The Galaxy Movie Trailer