Long gone are the days of emailing yourself important files, storing documents on your desktop or carrying a spare thumb drive, just in case. Data storage has made its way online, and Internet users have embraced the cloud.

Websites and smartphone apps like Dropbox, Amazon S3, Google Drive and MediaFire promise secure, convenient places to store and share files online. Users can access the information from anywhere, anytime with their username, password and an Internet connection.

These services aren’t just for the most tech-savvy, either. A report released last fall by Illinois-based Forrest Consulting found about two-thirds of adults in the United States use at least one cloud service. Sixty-five percent of adults are storing files, contacts, and photos on the web, according to the survey.

About 15 percent of American adults use file, media, and information syncing services, the survey found. Those numbers are growing rapidly. In 2010, just 9 percent of adults used such services.

Another study, released by Strategy Analytics in March, found Apple’s iCloud and iTunes Match and Dropbox the most popular personal cloud storage options. Twenty-seven percent of the 2,300 people surveyed were connected to Apple services, compared to 17 percent using Dropbox.

Amazon and Google Drive each scored 15 and 10 percent of users, respectively. No other service captured more than 4 percent of users surveyed.

The latest cloud-storage option on the market? EntourageBox, a site that let’s users share files with anyone, regardless of which (if any) cloud-storage site they use.

Users connect to EntourageBox with their Dropbox, Amazon or Google accounts and create a folder. EntourageBox creates a link to the folder that can be shared with anyone, without the hassle of a creating an account or remembering another password. The URL can be deleted or deactivated at any time.

All of these services have their appeal: access to files from any computer or phone, desktop and mobile apps and seemingly endless online storage (for a price, in most cases).

They can also make sharing the newest book, CD or movie with a friend a whole lot safer than downloading a free copy from a file-sharing site. Peer-2-peer file sharing sites, often shortened to P2P, are loaded with viruses, malware and spyware just waiting to worm their way onto your hard drive.

Still, the cloud isn’t a perfect solution for sharing information safely on the web. As with any website, they can be compromised. Use the tips below to keep your data safe.

Know Your Rights: Read the privacy and security policies. Yes, it’s easy to skim over the fine print, but it’s the only way you can be sure you’re protected if a site’s security is compromised.

Be Smart: Every piece of information you put on the cloud has the potential to fall into the wrong hands. Even trusted sites can fall victim to hackers or leak passwords and usernames — dangers that could compromise those account numbers you uploaded or that credit card information you stored. Don’t put info on the cloud you’re worried could fall into the wrong hands.

Watch Your Kids: You might know what’s appropriate to put on the cloud, but your kids might not. Be on the watch for personal photos or identifying information making its way online. Make it clear what can be shared and what shouldn’t.

Be Picky: Choose a cloud-storage service that feels right for your needs. Saving a few extra dollars might not be worth it for a site you don’t feel safe or comfortable using.

Second Guess the “Remember Password” Feature: In the unfortunate event your laptop or cell phone goes missing, a criminal could easily stumble upon your personal data logging into your cloud-storage account is just a click away. Typing in your password each time you log in isn’t so bad.

Stay the Course: Jumping from service to service to get a better deal could put your data at risk. The more places you’ve got that list of passwords, the more copies of it exist online. Unless you’re genuinely unhappy with your cloud-storage site, stick with it.

Guard Your Passwords: Don’t give out your login information or write it down where someone else could find it. It only takes one misplaced Post-It note for disaster to strike. Creating strong passwords is also key. Something predictable or easily guessed won’t hold up if someone tries to access your information.