DBFeeder is a great tool to generate synthetic testdata for Oracle Databases and it is ideal for companies who wants to outsource development. Thanks to his original approach, data can be highly customizable and it even fits primary and foreign keys constraints of tables.
benerator is a framework for creating realistic and valid high-volume test data, used for load and performance testing and showcase setup. Data is generated from an easily configurable metadata model and exported to databases, XML, CSV or flat files.