CHARLOTTE, N.C. — The elements of a hard-earned vacation: beach, mountains or amusement parks, rest and relaxation, and, all too often, e-mail and cell phones.

In this fast-paced, 24/7 BlackBerry age, more American workers — particularly those with important-sounding titles or ambition — are finding it's impossible to ever really get away from the office. Taking vacation often means taking work along, too. There's no abandoning clients or ignoring phone messages when hitting the beach or visiting Mickey with the family.

But while it's nearly impossible to fight it, you can set boundaries.

Heading into summer vacation season, Americans more often are combining work and fun. A study last year by Hudson North America found that about a quarter of workers check e-mail and voice mail daily or almost daily while on vacation.

One of them is Jeff Blackey of US LEC Corp.

"I feel responsibility to my job and to the company to stay up on things and make sure things are running along smoothly. And, quite honestly, I don't want to come back from vacation to a mess," said Blackey, senior vice president of marketing and business development for the Charlotte-based telecom services company. He has also been known to dial into business meetings while on vacation with his wife and two sons.

So prevalent is Blackey's attitude and the notion that vacation doesn't mesh with career success that when Wal-Mart CEO Lee Scott recently announced he was taking off the entire month of May, the retailer had to quash speculation that he was resigning or being fired. In 27 years at Wal-Mart, Lee had never taken off more than a week at a time, according to a recent article in The Wall Street Journal.

Workers need to do a better job of balancing work while on vacation, said Robin Bond, a lawyer in southeastern Pennsylvania who specializes in workplace issues.

"Employees fear that if they have to leave the office even for a week that the employer may realize that he doesn't need him anymore," Bond said. "So there is an epidemic perhaps, well, I don't want to say of self-importance. It's fear."

Mixing work and time off might sound inefficient and not at all fun. But with the right attitude and plan, a working vacation can actually be relaxing, say those who have done it.

Bond, who advises Fortune 1,000 companies, recommends designating a triage person back at the office. This person will know how to reach you in true emergencies and will filter out all the noise that you really don't need to respond to right away.

Laura Mercer, 46, a public relations executive, was tired of vacations spent working while her husband and two children shared moments, such as a memorable visit to the battleship North Carolina in Wilmington, Del. Another beach vacation was interrupted when a client's plant was on fire and Mercer was up all night in crisis-management mode.

Before a trip to Orlando, Fla., in March with her husband and 18-year-old son, Mercer came up with a plan to keep her clients and family happy and to take it easy.

With son Cortland headed to college in the fall and daughter Sarah already in college, "it just kind of hit me that this was going to be my last chance to have a vacation with one of my children and I wanted to enjoy it," said Mercer, a partner at Eric Mower and Associates, whose clients include Northlake Mall, Nucor Corp. and Sun City Carolina Lakes.

She drew up a plan, starting with her goal:

"Make sure clients are taken care of but that I get to relax."

She made preparations, telling clients she'd be gone for a week, arranging backup support at the office and accelerating critical projects before she left.

Mercer also set up rules for how much time could be spent on work while in Florida. She could check e-mail twice a day — early in the morning and again at night. She permitted herself one voice mail check-in at midday. Without those rules, she knew work could easily take over vacation as it had in the past. But she also knew she couldn't go totally MIA, because she'd be too worried about work to have fun.

"It's almost like when you are on a diet and allowed one Oreo cookie," she said.

Her plan worked, she said, adding, "I really felt like I focused more on the fun part and I didn't mind working." She'll implement it again this summer when she and her family head to the beach.