I was recently prompted for access to my keychain for librariand and ubd. I see librariand and ubd as:
/usr/libexec/librariand
/System/Library/PrivateFrameworks/Ubiquity.framework/Versions/A/Support/ubd
I didn't see prompts for keychain access to these processes before I enabled iCloud on that system. Afterwards, I was prompted.
A man page exists for ubd and talks vaguely about "Mobile Documents."
I suspect these are both are related to iCloud somehow. This would help explain why they are new to Lion and not present on Snow Leopard.
The name of the framework, "Ubiquity," is pretty interesting in and of itself.