Don't tell anyone, but the secrets you share in the office with your most trusted colleagues and co-workers really aren't. Secret that is. 

A recent Harris Poll was conducted for CareerBuilder, and reported by USA Todayand found an astonishing amount of sensitive information is left out in the open by workers for prying eyes to see, and what should be private, confidential conversations often end up becoming public.

"Employees always want to be mindful about what they say and do at the workplace," says Rosemary Haefner, chief human resources officer at CareerBuilder.

About half (53%) of the staff workers surveyed say they have overheard confidential conversations at work. Of those folks:

• 62% have heard conversations with people complaining about the boss or other workers

• 35% have heard conversations about layoffs or firing someone

• 22%, conversations about someone's compensation

• 20%, conversations about romantic relationships between co-workers

• 18%, lying to the boss

• 11%, setting up a co-worker to fail

Among the unusual items the support staff have found: A list of employee salaries; a photo of a partially-dressed co-worker; layoff and compensation paperwork; an upcoming reorganization diagram; a letter from the boss's mistress; the boss's s ex-wife's bank account statement; an employee's tax return; stolen event tickets; a diamond ring; an old love letter from one person in the office to another; information about a breast augmentation; a pregnancy test; and an employee's response to a personal dating ad.

"While most of the information that was found or overheard was relatively harmless, it's always important to practice discretion when it comes to handling personal, private or sensitive matters," stated Haefner. "For example, more than one-third of support staff said they overheard conversations concerning layoffs or terminations, which can have a greater negative impact if the information is not handled properly."

The bottom line lesson from this study?

"Keep personal business to a minimum in the workplace and be careful about information you discuss, e-mail and print," Haefner says. "What you thought was a private conversation in the hallway can be public knowledge within minutes."