When I travel, I often don't carry a travel alarm. Instead, I generally rely on my mobile phone's built-in alarm clock feature. During this trip, I discovered that's not such a good idea because of unexpected interdependences in technology.
You see, my phone sets its current time from the cellular network, which is handy because it means the phone's clock is usually very accurate. But the phone is not an international model. So when I turn on the phone here in Japan, it gets stuck looking for a cellular network, which it's never going to find because the network is on a different set of frequencies. So there's no way to get to the alarm clock function because the phone's stalled on the network search. And there's no way to manually set the time. Rather than degrading gracefully to let me use the other functionality, the phone's basically a very sophisticated electronic paperweight.
My old Palm Pilot has an alarm clock feature as well, but I've been hesitant to use it because, to make sure I wake up at the right time, I'd need to change its clock to local time. But Japan's on the other side of the international date line from the U.S. I have no idea what happens if I advance the clock, make an entry, and then upon returning to the U.S. reset the clock to what the Palm Pilot will believe is the previous day.
So far, we've been using wake-up calls at the hotels, which are an automated system at the places where we've been staying. They've been working out pretty well, but that's a heck of a lot of technology to rely upon, and the tour guides are sticklers for punctuality.
Maybe next time I'll just bring an old fasioned mechanical wind-up alarm clock.