Online Computer Backup

Lately I've been researching online backup services. For some reason backing up data is always on my list of things to do that I never seem to get to. I hate this, because in the back of my mind, I am always afraid of losing important data - especially important client data - that could sabotage my business. Does anyone have recommendations for the best service to use? I've narrowed down my search to the following companies:






My biggest question: do either of these companies have experience working with parallels software? How would I go about backing up data on both operating systems - Windows XP and Mac OS10?