Happy to hear that MongoDB 2.2 has been finally released. Looking forward to use the aggregation framework & co.
A really nice and comprehensive article about NoSQL Data Modeling Techniques. Sums up the different strategies you can use with
Neo4j is a graph database, storing data in the nodes and relationships of a graph. The most generic of data structures, a graph elegantly represents any kind of data, preserving the natural structure of the domain.