Sexual harassment, profanity, and absenteeism were probably all covered in your company orientation. But chances are, a few egregious behaviors-like gossiping and bullying-didn't make their way into the employee handbook. Even so, these missteps might be grounds for immediate dismissal. Read on as we reveal seven on-the-job blunders that could get you fired.

1. Gossiping. You may think of it as idle chatter, but engaging in juicy watercooler conversations could be risky business. According to a 2005 issue of HR Advisor, workplace gossip can reduce productivity, alienate employees, and break down trust within teams. In some cases, the office rumor mill could even earn you a pink slip. In 2007, four town employees in Hooksett, New Hampshire, were terminated after discussing false rumors of an improper relationship between the town administrator and another employee.

2. Sharing too much information (TMI). Among friends and family, your life may be an open book, but revealing too much information at work could be an instant career-buster. This is especially true when it comes to personal medical issues, family secrets, or relationship problems. And don't even think about sharing the details of your intimate encounters-remember, although you may be friendly with your coworkers, it's always important to maintain a professional demeanor on the job.

3. Chronic lateness. When it comes to getting to work on time, you may think "better late than never," but your employer probably feels differently. According to experts, tardiness costs U.S. businesses more than $3 billion each year in lost productivity. And the effect on the bottom line is significant: An employee who's 10 minutes late every day has, by the end of the year, taken the equivalent of an entire week's paid vacation.

4. Fowarding Spam. Whether it's a chain letter that promises to bring good luck or a YouTube video of silly pet tricks, it's not appropriate office communication. Nowadays, there's email overload in virtually any workplace, and forwarding SPAM to your colleagues will probably just annoy them. Plus, your boss may be watching: According to the 2001 Electronic Policies and Practices Survey, nearly 62 percent of employers exercise their legal right to monitor employees' email.

5. Warbdrobe Malfunctions. These days, lots of office dress codes are business casual—but that doesn't mean anything goes. In a recent U.K. study, employers were asked which habit they found most annoying among employees, and more than 25 percent responded that it was unsuitable clothing or appearance. Moreover, according to a survey by California-based staffing service Accountemps, nearly 40 percent of managers said they thought workers appeared too casual when dressing down.

6. Being a Cellphone Addict. Mobile phones are invaluable devices for touching base, making plans, and averting catastrophes. But at work, you should be focused on the job at hand--not chatting with Mom from your cubicle. The problem is, some cell users are so addicted that they duck out of meetings to answer their phones or send text messages. Instead, turn off the ringer from nine to five, and if you must talk on the phone, do it from a private area.

7. Bullying. As it turns out, bullying isn't just found in schoolyards. A growing body of research suggests that intimidation and abuse run rampant in the workplace. According to the Workplace Bullying Institute (WBI), on-the-job bullying can be defined as "repeated, health-harming mistreatment" that may include verbal abuse, offensive conduct, or sabotage. Although historically, workplace harassment guidelines are limited to guarding against sexual and racial discrimination, since 2003, 13 states have introduced some version of the Healthy Workplace Bill to address status-independent harassment.