The oh, don't forget site offers an easy way to send yourself (and other people) reminders to a mobile phone. An API for this would be great...you could (theoretically) send all your iCal appointment alarms to the service.
A text message love affair gone wrong. "How had we managed to speed through all the stages of an actual relationship almost solely via text message? I'd gone from butterflies to doubt to anger at his name on the screen, before we even knew each other."
Two Morse coders beat two text messengers on Leno. That's it...I want a phone with one big button with which to tap out messages.