This is just a very quick and simple reminder for some, and a possible bit of news for new Verizon iPhone owners (welcome aboard, by the way).
When set to on, the iPhone’s silent switch will mute basically everything on iOS, except for the iPod and Clock application. This means that any alarms or timers that you may have going will sound despite Silent Mode, so watch out for this during lectures and important meetings. This is something my best pal didn’t know about his new iPhone 4, so I figured it might be helpful to spread the word.
[Note that you could set an alarm to ring without any sound at all, but if you do try this, know that you won't even get a vibration alert from your iPhone (just a completely silent pop-up).]