Google announced that one area of application for Glass will be vocational education/practice (NY Times article). Google Glass could be used to access information in the field (hands-free, voice controlled), for example checklists or patient information, and streamline communication. Such applications could be useful for on-the-job training by showing handbook information and tutorial videos as needed.
The company Wearable Intelligence developed two Glass applications, one for healthcare and one for pipeline maintenance.
Here is the pipeline maintenance video:
Another company, Daqri, is proposing a helmet with integrated augmented realty functionality - particularly for industrial workplaces.