Since I'm reverse engineering quite a number of embedded firmware images lately, I have started a new project called 'reveng-tools'.
The idea is to provide a set of tools that can be handy if you want to do that kind of work. For one part, you need a tool to scan a binary for signatures of well known file/compression/archive types. This part is already finished and called 'magic_ofs'.
I'm now working on an endian-safe cramfs extractor and a bFLT de-compressor. Stay tuned.