some links and references:

• 80mm OM lens hack - Mounting an OM Macro Lens on a Kiev-60
• Camera mounts & registers
• How to make an Olympus Pen F/FT/FV to Nikon lens adapter
• Leica R & M lens mount adapters ?
• Non-Canon Lens Adapters - Expanding the range of your Canon Camera
• Novoflex
• Using Manual Focus Lenses on Canon EOS Bodies
• Using manual lenses and telescopes with EOS cameras.