6. Use Offline Maps
Accessing maps online (or using apps that do the same thing, as the Google Maps Android app does) sucks up a ton of data. If you travel often, storing maps on your Android device instead of accessing them online will save you money and could even save your life if you get lost in a location where your phone doesn't work (places like remote roads, mountain passes, or even a foreign country).
There are plenty of great offline map apps for Android, including the default Android map app: Google Maps. To download sections of a map for offline use in Google Maps, open up Google Maps and tap the "…" button. Navigate to Settings, Labs, and check Pre-cache map area. You can now download sections of Google Maps (one 10-mile radius at a time) by tapping an area on the map, waiting until an address loads, tapping the arrow, scrolling to the bottom of the screen, and tapping the "Pre-cache map area" option. These downloads take a few minutes, but they're worth it if you know you'll be offline. Make sure to download them over a Wi-Fi connection to minimize your data usage.
7. Don't Stream
Streaming music and movies from services such as Netflix, Hulu, Pandora, and Spotify is a huge data drain. According to PCWorld's tests, watching YouTube videos for just 10 minutes per day can easily push you past 1GB in a month, while listening to Pandora for 1 hour per day uses about 1.76GB of data in a month.
The obvious solution is to stop streaming media over your cellular data connection. You'll probably want to give up watching Netflix and Hulu over your data connection altogether--but if you happen to be a big Netflix or Hulu watcher and you don't have reliable access to Wi-Fi, you may want to consider upping your data cap.
If you can't live without your favorite YouTube videos, you can download the free TubeMate app, which allows you to download videos from YouTube and watch them on the go. Remember to do this over a Wi-Fi connection!
Chronic music streamers should check out the offline playback modes of their favorite streaming apps. Both Slacker Radio and Spotify offer offline playback modes, though you must be a paying subscriber to use them. Slacker Radio's offline playback mode caches your personalized radio stations, while Spotify's offline playback mode downloads all of your playlists so you can listen without a network connection.
8. Don't Obsessively Clear Your Cache
Another mobile browser tip: if you don't clear your cache often, you'll end up using less data because your browser won't have to constantly redownload images and other Website assets. If you like to visit the same Website often, obsessively clearing your cache forces your device to redownload the same basic information each time you visit the site. It's a waste of data, and if you use a task-killer app you might be wasting that data without knowing it.
That's because lots of Android task-killer apps automatically clear your phone's cache to free up memory. Clearing your cache occasionally is a smart idea, but if you rely on a task-killer app, you're probably doing it too much and wasting data. Since you own an Android device, it's a safe bet that someone told you to download a task-killer app, such as Advanced Task Killer Free, to maximize your battery life. However, PCWorld tests have shown that task killers don't really work all that well--at best, you'll eke out a few extra minutes' worth of juice. At worst, task killers can actually degrade your device's battery life.
9. Block Apps from Using Background Data
Lots of Android apps are designed to run--and sometimes even boot up--in the background. That's part of the reason why many Android users employ task-killer apps--to keep unnecessary apps from running in the background and wasting memory.
Having lots of apps running in the background also leads to unnecessary cellular data usage. The easiest thing to do is to make sure that your phone doesn't sync with servers unnecessarily; do this by navigating to Settings, Personal, Accounts & Sync, and turning the automatic syncing feature off. This change will ensure that apps like Gmail, Twitter, and VZ Backup Assistant aren't constantly connecting to the Internet and downloading the latest mail/Tweets/contact info. Instead, you'll have to manually download these updates.
You can take things a step further by blocking your apps from accessing cellular data networks while they are running in the background. You can use a free app like DroidWall to block apps from using data, but there's a catch--it works only on rooted phones. However, if you root your phone using this handy how-to guide, you can install DroidWall and control which apps are allowed to access your cellular data network.
10. Get Creative With Device Tethering
Both AT&T and Verizon have hinted about introducing shared data plans--possibly with rollover megabytes--but we've yet to see anything concrete. While we wait for these mythical plans to come about, we can (sort of) simulate them with some clever tethering tricks.
For example, I own a Verizon Samsung Galaxy Nexus with a (grandfathered-in) unlimited data plan. I also own an AT&T 3G iPad. Instead of paying for data on my iPad ($30 for 3GB), I pay Verizon an extra $20 for the ability to tether my iPad to my Nexus when I need an on-the-go Internet connection.
Tethering often costs more than just paying for additional data, so use caution; review your data plan beforehand to verify that this tethering trick is a good idea.
These are merely a few ways that you can use less data and (hopefully) pay a lower wireless bill. Go forth, use less data, and share your creative tips for circumventing cellular data caps in the comments!