"Hey, let's all meet at Bill's party around 8pm." And that conversation was the last time you saw half of your friends. Tonight is going to be insanity. You'll be lucky you even make it to midnight, let alone keep your group together. But you know what, let's try it anyways.
Before you head out into the night, you'll need to get your friends to install or sign up for a few services. This will probably the most difficult task of the evening if it all goes to plan. Of course, none of it will go to plan, but at least you made the effort.
Don't bother with your phone's texting app. Some phones will allow group text, while others won't. And you have that friend that's still rocking the flip phone from seven years ago. Instead, download GroupMe. It's cross platform and it'll work on dumb phones. It's the official app of the Gizmodo crew at CES and when we go out at night. Seriously, we're always together. ALWAYS.
Set up the app to use SMS or as a chat application with push notifications. In addition to chatting, users can share location and photos. Once the festivities are over, uses can mute a group chat so they can get some sleep while the rest of the party crew rocks the night away.
Speaking of Location! Google Latitude is your stalking app for the night. Instead of trying to get directions from someone that's already had five beers, Latitude can pinpoint their location. There's a native app for Android and iOS. Windows Phone will have to use the browser. If you want to be able to find each other without having to launch the app, be sure to allow background updating on your device of choice. At the end of the night, you can turn it off.
Finally, charge your phone. Keep it on the charger until you leave tonight. If you're on an iPhone, we've always been big fans of the Mophie juice pack air battery case. And while the state of Android accessories can be a little bit scary, PowerSkin has battery cases for a good range of handsets.
If you're particularly desperate, you might want to go ahead and take your charging cable with you; you never know what friendly bartender will let you mooch from his outlet, or what host has a spare USB port to plug into. It's demoralising, sure, but better than losing track of the herd.
The bottom line: you're going to be making a ton of calls, sending dozens of texts, taking photos, shooting video, and running these apps all night long. And you can't do any of those things if your phone is dead.
Please do share any other tips in the comments, and have fun!