OpenPuff is data hiding and watermarking made easy, safe and free.

It provides you with advanced Steganography and Watermarking - Image/Audio/Video/Adobe/Flash support.

OpenPuff Features:

Images support (BMP, JPG, PCX, PNG, TGA)
Audio support (AIFF, MP3, NEXT/SUN, WAV)
Video support (3GP, MP4, MPG, VOB)
Flash-Adobe support (FLV, SWF, PDF)
Windows Executable support (EXE, DLL)
Multiple carriers chains (up to 256Mb hidden stream)
Random per-block-cryptography (8 open-source algorhythms)
Strong cryptography (512bit key, password hex extension)
Data scrambling & Whitening
Adaptive LSB & Bits selection level
Multithread support (up to 64 cpus) = Faster processing
Simplified interface
Unzip program and help in the same directory
Portable - no need to install