Tyler Hobbes spoke to 85 Java developers about Cassandra, the NoSql database created at Facebook, but used by Netflix, reddit, ebay and instagram. My bullet points:
Cassandra has no Master-Slave architecture, but instead has a network of peers all sharing data.
Cassandra is fully distributed and has no Single Point of Failure (SPOF).
They use Murmur to build 64-bit hashes.
Yuki Morishita talked about Cassandra Query Language CQL.
You can use sqlsh, a command-line version of CQL.
Cassandra is not good for ad-hoc queries, the database structure has to be designed for your planned queries to be useful.