It's great to print your boarding pass at home or the office before heading to the airport on a trip.  Depending on the airport it can save half an hour or more...particularly when you are flying on an airline that doesn't have a strong presense in the at the airport from which you are flying.  However, once you get on the road and into the hectic nonstop activity of a busy schedule, it can become harder to find time to print at the hotel business lounge or the airport lounge.  One hack I use when I am pressed for time is to fax my boarding pass to the hotel at which I am staying. 

If you airline doesn't have a fax option (mine did briefly before it disappeared), it doesn't take much time to use a PDF printer (I use CutePDF under Vista) and an internet fax service (I use efax) to make it happen.  That way, my boarding pass is waiting for me when I get there to check in.