(CNN) -- Driving south from Ohio with his wife and two children on Thursday, Steve Daly stopped in Tennessee for what's advertised as the world's best ice cream. After ordering, he briefly switched out of vacation mode to check his e-mail on his phone.
His family nags him about his e-mail habits, but for Daly, it's the only way to have a good vacation.
"The anxiety is just not knowing -- so being able to check the inbox and see what's going on, if anything, is what allows me to relax," says Daly, 39, a self-employed technology consultant in Cincinnati, Ohio.
Daly is not alone. Many people can't go on vacation without worrying about their inboxes. And with the advent of smartphones, it's all too easy to keep work in your pocket when you travel.
"You keep business on you, so to speak, when you're trying to keep on top of everything else in your life," says Brian Uzzi, professor of leadership at Northwestern University's Kellogg School of Management.
With work and personal life integrated into smartphones -- and messages from your boss just one click away from a map of your destination -- it's difficult to separate the two, Uzzi says.
Surrounded by computers and handheld devices at work and at home, people are accustomed to having e-mail within reach nearly all day, making it hard to shift gears on vacation, says Kate Muller, director of psychology training at Montefiore Medical Center in the Bronx, New York.
The impulse to check messages frequently relates to a psychological principle called a variable reinforcement schedule, says Uzzi. That means when animals -- or humans -- are rewarded randomly for a particular behavior, it's harder to get them to stop the behavior than if they had been rewarded consistently for the same behavior.
So even though most of your e-mail may not be urgent or even interesting, every now and then there is something you really do want to know about while you're on vacation -- perhaps even just office gossip. It's hard to stop yourself from checking for those messages because they come through on a random basis, Uzzi says.
Ephren Taylor, 27, CEO of City Capital Corporation, is also intimately familiar with the problem of unwinding on vacation. A self-described "bonafide 'crackberry' addict," Taylor found himself with a phone bill of about $900 after coming back from Barbados with his wife for their anniversary in February. (Taylor is also the youngest African-American CEO of a publicly traded company -- watch an interview)
"It doesn't matter if you're asleep or whatever, you'll wake up and you'll see that red light, and you'll look at it," Taylor says of his BlackBerry. "It doesn't matter if you're having a romantic dinner on the beach or whatever it is. It can be a vacation-ruiner real quick."
But anxieties that people like Daly and Taylor experience don't mean that all communication devices should be left at home, or even that you shouldn't ever check e-mail on a phone, experts say.
One solution is to agree to a particular times set aside to check e-mail. For example, a few minutes after lunch, an hour before dinner, and a half hour before bedtime, Uzzi says.
Taylor -- who admits to having snuck out of bed to check his phone late at night -- has actually gone as far as to pick vacation destinations where cell phone data service might not work as well. One spot in the Dominican Republic, for example, gave him the limited coverage he desired.
But Taylor says shutting off the BlackBerry altogether or leaving it at home still isn't a perfect solution. The first unplugged vacation day is basically "withdrawal" as you wonder what's going on that you don't know about, he says.
It's important to not feel like you have to be "on vacation" the moment you pack up at the office on the last day before a trip, says Muller of the Montefiore Medical Center.
"Ease things down in that last hour before you leave so that there's some feeling of a transition -- we struggle moving from 'busy-busy' focused into this idea of relaxing."
If you're flying somewhere, give yourself a little time after you stop working before you leave for the airport, she says. The unwinding time can help change your focus and attitude.
Muller also recommends a technique called mindfulness: Being in the present moment at all times and not letting the mind wander too far ahead or back. It helps people relax and enjoy their vacations, she says.
Another strategy is to try something different, such as a sport you've never tried before, to stimulate and focus your mind, she says.
But what about the stress of returning home?
During a trip, distractions help you forget about work worries until the day you return -- and get the thousand messages you missed, Taylor says.
"All of the rest you got from the vacation goes out the door in about two hours."
This panic of the return can be lessened by taking simple steps starting the night before you go back to work, Muller says. Before going to sleep, take some "worry time" to write down everything you're worried about. Many people find that this enables them to feel better about those anxieties, she says.
When you return to work, try not to schedule anything within the first hour or two back -- sit down with your favorite morning beverage, put on some music, and go through your e-mail one message at a time. Don't worry about how many e-mails may be waiting for you.
Taylor already knows that wherever he goes on vacation with his family in August, his BlackBerry will stay at home. He and his wife agreed he will remove the SIM card from his BlackBerry and put it into a regular cell phone so that he can't get e-mail.