Und übrigens noch was ...: Douglas Adams' : Per Anhalter durch die Galaxis. Teil 6 der Trilogie - Eoin Colfer

Sorry for having to state the obvious here: This is not a book by Douglas Adams.
The main difference is that Douglas wrote SF with a portion of (wonderful) humor, while Eoin Colfer has written a comedy with SF elements. Still a really entertaining read, and the many references to the other Hitchhiker books made me feel all warm and fuzzy inside, so much that the fourth star is for merely sentimental reasons.

The last book in the series will now be "Don't Panic: The Official Hitchhiker's Guide to the Galaxy Companion" by Neil Gaiman.