Usage is simple, just use one of the flags: -m, -d, or -u, for traditional Mac, DOS/Windows, or Unix line endings. A -t option will just tell you the type of a file. For example, flip -d *.txt will convert all files ending in .txt to DOS end-of-line characters.
[robg adds: This older hint explains (in the hint and the comments) how to use text editors and/or the command line to convert between Mac and Unix line breaks, but I thought it might be time for a new hint with another solution...]

