Claus Wahlers just released an update for FZIP, a AS3 class library to load, extract/decompress files.

Main updates are:

• Added support for Adobe Air. The Adobe Air runtime provides a low level inflate method, making it possible to load any ZIP archive and decompress compressed files without the need of injecting Adler32 checksums.
• Added FZipLibrary class for higher level access to files in a ZIP archive. ?FZipLibrary processes files (based on file extensions) from an FZip instance and converts them into usable formats. Files can be converted to either a BitmapData or DisplayObject classes. Data embedded in SWF files (like classes) can also be retrieved. Flash?s built-in Loader class is used to convert formats, so the only formats currently supported are ones that Loader supports. As of this writing they are SWF, JPEG, GIF, and PNG.?
• Bug fix: There was a problem with filenames containing special characters. Filename encoding now defaults to UTF-8. In case the filenames are encoded differently in your ZIP, you can specify the encoding in the FZip constructor.