What is the easiest way to adjust EXIF timestamps on photos from multiple cameras in Windows Vista?

Scenario: Several people go on holiday together, armed with digital cameras, and snap away. Some people remembered to adjust their camera clocks to local time, some left them at their home time, some left them at local time of the country they were born in, and some left their cameras on factory time.

The Problem: Timestamps in the EXIF metadata of photos will not be synchronised, making it difficult to aggregate all the photos into one combined collection.

The Question: Assuming that you have discovered the deltas between all of the camera clocks, What is the simplest way to correct these timestamp differences in Windows Vista?

Solution

Windows Live Photo Gallery Wave 3 Beta includes this feature. From the help:

If you change the date and time settings for more than one photo at the same time, each photo's time stamp is changed by the same amount, so that the time stamps of all the selected photos remain in their original chronological order.

Instructions:

Select Photos to change (you can use the search feature to limit by camera model, etc).
Right-Click and select 'Change Time Taken...'.
Select a new time and click OK.

Current download location is from LiveSide.net.