I asked in a previous post whether it was fine to re-run Time Crunch with different exercises but I realize I neglected to ask a related question: Apart from Time Crunch, which programs have the workouts that take the shortest amount of time, comparatively?
I think if you reduce your rest periods to 2-3 minutes and are efficient with your equipment set-up, pretty much anything except strength II or III would work on a limited time budget.