Managing your 250MB iPad 3G plan

Macworld - What's it worth to you to save $180 a year? That's the difference between the two cellular data service plans offered by AT&T in the United States for the 3G iPad.

For $15 per 30-day cycle, you can consume a combined total of up to 250MB; unused data isn't rolled over, so it expires. For $30 per month, AT&T provides truly unlimited data--as with the iPhone 3G and 3GS plans.

I don't know about you, but if it means saving $180 over 12 months, I'm willing to be a little creative.

That $180 savings is in the U.S. only, of course. Carriers in Europe and Japan just announced service plan pricing for 3G iPad service, and none of those plans include unlimited use at 3G speeds. Typically, even with a monthly plan, you can pick a limit between 200MB and 10GB, depending on country and carrier.

Pass the limit and you're either cut off (and sometimes, like with AT&T, can top up with another purchase), or your connection is throttled over a cellular network to 64 Kbps for the remainder of the current billing cycle.

David Chartier already tackled the many ways in which you can burn 3G data. I'll elaborate on strategies that let you keep your data usage over cellular as low as possible.

Turn off, tune out

First, learn the location of the iPad's all-important Cellular Data switch. Found in the Settings app in the Cellular Data section, this switch controls whether an iPad uses a cell data connection when one is available or not.

If you're not using AT&T's unlimited plan--you have its 250 MB plan or are signed up for 3G service outside the U.S., which always has some limit--you should plan to set Cellular Data to the Off setting unless you specifically need access.

By just keeping Cellular Data set to On, all the various background activities that an iPad can perform even with iPhone OS 3.2 still occur and consume data. You should separately disable those actions, too, but keeping Cellular Data off removes accidental usage.

When you need to use 3G, sip don't slurp. Turn on the Cellular Data option for particular tasks, such as reading e-mail, viewing Web pages, or downloading a particular file. Then, when finished, turn it off right away.

Putting your iPad to sleep doesn't stop data from being received; only turning off Cellular Data discontinues any unintentional data usage.

Flip switches, change settings

You can slim your 3G profile in other ways by taking precautions before hitting the road and burning data.

Turn off push: In the Settings app in Mail, Contacts, Calendars, tap Fetch New Data, and set Push to Off. If you leave Push set on, your iPad will be in regular communication--at an interval you set in the Fetch section below the Push switch--with servers to retrieve data.