textually.org: SMS opens doors to toilets in some rest areas along Highway 1 in Western Finland
Now that's an intriguing idea-- in order to access the toilet, you send a text message. Since they (presumably) keep your mobile number on file, they know who went in on any given date/time-- which makes end users less willing to vandalize the toilet.
Oh, sure-- the naysayers can find 20 million things wrong with this approach: what if I steal someone else's cell phone and use it, or what if I use a cloned SIM chip, or what if I wait until someone else uses their mobile to open it and then sneak in behind with them, etc.
Maybe this will replace some of those ridiculously proprietary RFID keycard systems (separate database instead of integrating with Active Directory?!?) that people currently love to use to regulate after hours building access.