Share a ZFS file system over SMB/CIFS and advertise it via mDNS so that it shows up in the OS X Finder. Assumes SmartOS, but should work fine on any illumos distribution.
# Allow guest access to a trusted subnet
zfs set sharesmb=ro=192.168.1.0/25,guestok=true,name=store zones/store
# Advertise the SMB service, it will now show up in Finder
dns-sd -R "Loft Server" _smb._tcp local 445 &
# Give it a pretty icon. If you want something different, choose from the list in
# /System/Library/CoreServices/CoreTypes.bundle/Contents/Info.plist (use plutil to
# '-convert json -o /tmp/out.json' first).
dns-sd -R "Loft Server" _device-info._tcp local 445 model=RackMac &