In 2.2.1, all I have to do to clear the RAM on the device is long tap the home key, then choose task manager and then go to the RAM manager to clear the RAM. I'm finding that this has been changed in 2.3.4. How do I clear the devices RAM in 2.3.4? The device that I have is the Nexus One.
Your previous Task Manager was a Samsung addition, and not part of Android itself.
In 2.3 onwards there's a very similar and memory usage listing. If you go into Settings, then into Applications and click the "Running Services" option, it should show you everything that's running along with how much memory it's using. There's also a small graph at the bottom showing RAM used vs RAM free.