I've used web check in without a printer at times when I know I will be running very late, and want to get a descent seat e.g. on the shuttle. Again, the ticket agent can reprint the boarding pass.
Also sometimes when I use web check in at a hotel I will send the boarding pass to a fax printer in my laptop and fax the document(s) to the hotel. You can either do this through a connection to your corporate faxing software or even with Windows an an ordinary fax modem. I then present the fax bp at security and when boarding the plane and have never had a problem.
Has anyone though done web check in, and then gotten the kiosk to re-issue a boarding pass? The kiosk has been mentioned, but can anyone verify that the kiosk would re-issue the pass?