Cloud solutions are becoming ubiquitous. Cloud or Hosted services can give your company more freedom add to your security and save you money over traditional network infrastructure. Which services your company should use depends upon your size, the type of business you are in, how many locations you have, and even cash flow.
You are probably already using several of these more obvious solutions that offer a real benefit and have few if any downsides.
Cloud Email Spam Filtering
Cloud Based Anti-Virus
Cloud Solutions that may or may not make sense for your company
Hosted Line of Business Applications - SAAS