YAML serialization library for C++?
A quick search gave me this: yaml-cpp
Try the YAML component from the BOOST vault serialization library.
EDIT 2014: A recent development, https://groups.google.com/d/msg/boost-devel-archive/mhT7qIh1nsI/uXAuXFAWrxQJ
EDIT 2019: Didn't try it yet, but this seems to be a serious take: https://github.com/rwols/yaml-archive