You can indeed do it fast, but the proper way is to do all 4 at once so that everything is aligned as one, not two separate alignments, one front and one rear. The 10-minute way may work out just fine or it may not.

My new used X was aligned under warranty as the steering wheel was off-center a hair. The head tech did the job and I sat there, walked to Starbucks, read magazines at Borders and actually watched soccer on the dealer's plasma. All this took over two hours.

Generally I don't trust dealer alignments and usually go to the best independent in town, but under warranty and having the head guy do it is fine and I can't complain about steering or tracking at all now.