ScoopyNG — The VMware detection tool (http://www.trapkit.de/tools/scoopyng/)
ScoopyNG combines the detection tricks of Scoopy Doo and Jerry as well as some new techniques to determine if a current OS is running inside a VMware Virtual Machine (VM) or on a native system.
ScoopyNG is able to detect VMware even if "anti-detection-mechanisms" are deployed.
FAQ — Interpretation of results
Q: How do I know if it's indeed a VMware Virtual Machine?
A: If one or more of the test results state that VMware is detected.
Q: Do all the tests have to state that it's VMware?
A: No, it is sufficient that one test result says that VMware is detected.
Sample results Sample 1: native, Windows Vista SP1 32bit, Intel(R) Core(TM)2 Duo CPU
Sample 2: VM, Windows Vista SP1 32bit, Intel(R) Core(TM)2 Duo CPU, VMware Workstation 6.0.4 build-93057, without anti-detection-mechanisms
Sample 3: VM, Windows Vista SP1 32bit, Intel(R) Core(TM)2 Duo CPU, VMware Workstation 6.0.4 build-93057, with anti-detection-mechanisms
Citations The tool is cited in various academic journals (e.g. here or here) and books