This is also important to note because Google Apps has much more in common with AdWords and Google.com than it does Office or Exchange Server. Google.com and Adwords run on MapReduce, BigTable, and Google File System - in 2010 Google made massive investments in infrastructure to support these systems. Google.com and Adwords are not the only SaaS applications that run on these systems. Google Apps also runs on MapReduce, BigTable and Google File System. This is the benefit of having an actual cloud computing infrastructure rather than just television commercials.
If your employees are leveraging Dropbox to get work done, you should give them Dropbox. More importantly, you should control Dropbox in the same way the firm manages other technologies - email, calendaring, the phone system, laptops, project management, Word, etc.
Umzuzu is a small, bootstrapped firm in the Kansas City area. Certainly year 11 is much easier than year 1, but we never forget our roots. We understand the desire and value of the DIY projects. They can often save money, especially initially. But as we all know, DIY projects can be surprisingly complex!