If you really want to try and play with MapReduce on a dataset without going through setting up a Hadoop node (or 4), check out CouchDB. It's designed around M

If you really want to try and play with MapReduce on a dataset without going through setting up a Hadoop node (or 4), check out CouchDB. It's designed around MapReduces (though not distributed), and you even get to deal with solving re-reduce problems.