Need a distributed key-value lookup system

Question

I need a way to do key-value lookups across (potentially) hundreds of GB of data. Ideally something based on a distributed hashtable, that works nicely with Java. It should be

Answer 1

OpenChord sounds promising; but i'd also consider BDB, or any other non-SQL hashtable, making it distributed can be dead-easy (if the number of storage nodes is (almost) constant, at least), just hash the key on the client to get the appropriate server.