Chameleon Shutdown is a handy little software that gives you the flexibility to put your PC in different states whenever you want. It's not just the one condition, but you are allowed to configure multiple conditions to trigger putting PC in the desired state. I've checked it on Windows 7 and on XP professional system and found no glitch in the working. You can also configure it to start automatically every time you boot your system. This prevents repetitive configuration of triggering parameters. Following are some of the conditions that can be easily assigned through an easy-to-use interface.

Delay - Through this option, you can delay hibernation, shutting down or locking down for up to 2 hours 30 minutes. You can choose from different time frames available in the list whichever fulfills your requirements. This condition is very useful when you know the approximate time of job completion currently running on your system. This can be a large file download or a large project compilation. Simply select the appropriate time and choose the desired state. Make sure you add 5 to 10 minutes in the approximate time to trigger shutdown or hibernation only after the job is completed successfully.
Specific time - This is yet another useful condition which can be used liberally by any user using this software. If you know the exact time to shutdown or hibernate your PC, simply select this option and set the exact time. As soon as the system clock will reach that time, system will go in the desired state as configured earlier by you.
Idle time - This condition is very useful for users who spend an almost whole day in front of the PC taking frequent breaks throughout the entire day. Whenever you choose this condition and set the appropriate duration, the software looks for activity in your system's mouse and keyboard. If there is no activity in both for the specified duration, the system is sent to the desired state.
CPU usage - If you're doing a long CPU-intensive task, this condition is ideal for you. It continuously monitors the CPU usage rate for the assigned duration. If the CPU usage is continuously below at the assigned level for a specific duration, the trigger is fired to hibernate or shutdown your PC. Users should carefully use this option as applying very low CPU usage level may never trigger the operation.
Closure of a program - Now this is one of my favorite options. When you opt for this condition, you're presented with a list of all the running programs in the memory. You can choose the target program and can set the appropriate state. Now, whenever your chosen program will be closed (manually or automatically) your PC will be sent to the desired state. I've used this option the most and found it extremely useful in several conditions.
Configuring multiple conditions - This is the most powerful feature of this software. As I mentioned earlier, you can easily assign multiple conditions for putting your PC in the desired state. You can use your imagination and can find different useful conditions that may need system shutdown, hibernation or lockdown. You can use 'AND' and 'OR' switches between each condition to build a flexible and complex hierarchy of required conditions.

Note: If you're going away from your PC, you must disable confirmation prompt window which pops up whenever trigger is fired.