Sadly, MongoDB blows for actual usage. It locks, it's not crash-only, it has mutable data. CouchDB is much better (you're as likely to lose data as with Postgr

Sadly, MongoDB blows for actual usage. It locks, it's not crash-only, it has mutable data. CouchDB is much better (you're as likely to lose data as with Postgres), but is potentially less efficient (no BSON).