How to test our Oracle database environment for free

If you want to benchmark your new Oracle9i/10g database environment before to put it in production as a part of your migration procedure, then may be you are one of these who are facing with the problem: How to test my database, where to find a proper tool or program and how much I must pay for that?
I just want to share a links to several free programs that can help you to test your Oracle database:
1. Swingbench is a free load generator (and benchmarks) designed to stress test an Oracle database (9i or 10g). The entire framework is developed in Java and as a result can be run on wide variety of platforms. It also provides a simple API to allow developers to build their own benchmarks.
This tool is developed by Dominic Giles of the Oracle9i Solutions Group. It is designed to be used for Oracle RAC environment but it can be used to benchmark a single databases as well.
2. Another tool - ORION was mentioned in the Jeff Moss's Blog, here: ORION - Oracle I/O Numbers calibration tool and here: ORION Usage and Futures
ORION is developed again from Oracle and is an Oracle I/O Numbers Calibration Tool designed to simulate Oracle I/O workloads. ORION is useful for understanding the performance capabilities of a storage system, either to uncover performance issues or to size a new database installation.
You can use this tool to stress and test your storage system even before to install an Oracle database on your servers. Oracle provides an Users Guide on the home page of the tool.
3. Hammerora is an open source load generation tool for the Oracle Database versions 8i,9i and 10g on the Linux/UNIX and Windows platforms.
Steve Show is the author of Hammerora project. Steve is a senior database consultant for Intel Solution Services, specializing in Oracle Real Application Clusters on Linux. He is also a co-author of the forthcoming book from APress: Pro Oracle RAC on Linux: Installation, Administration, and Performance
4. Apache JMeter is a 100% pure Java desktop application designed to load test functional behavior and measure performance. It was originally designed for testing Web Applications but has since expanded to other test functions.
This tool simulates a heavy web traffic and can be used to benchmark your Oracle Application Server or local HTTP server.
To download the latest version: JMeter Downloads
I would really appreciate if you leave your comments here to share your own experience with some good free benchmark tools. My intention is to update this post with them and to create a complete list with similar programs.