There's a new module available in the repo: chat-messages stores your chat messages in daily archives.
There are already 2 programs using it in production:
hubot-remotestorage-logger is a Hubot script which lets you log your IRC messages to a remote storage (soon other protocols as well, help welcome)
rs-messages-importer is a command-line tool for importing chat log files to a remote storage (currently only from ZNC, help for additional sources also welcome, of course)
If you want to use this and/or have any questions, feel free to add them to this thread or open a new one. We're hanging out in #67p, #kosmos and #remotestorage on Freenode, too.