The National Institute of Standards and Technology has released a draft guideline on staying secure when using cloud computing. More companies are putting their IT infrastructure and data into The Cloud, but there are risks associated with giving a critical part of your business to another company. NIST is a US government agency that’s well respected in the security industry, and I highly recommend reviewing this and other guidelines they’ve produced before you drink the Cloud Kool-Aid.
http://csrc.nist.gov/publications/drafts/800-144/Draft-SP-800-144_cloud-computing.pdf