One of my recent project was to support and perform some enhancement on a MOSS 2007 for our provincial government. Due to the nature of the government, every production deployment is a complex process, it requires different level of QA, different approval from IT and infrastructure approval and lengthy change request... In short, if you have created a simple "Hello World" webpart, it will take at least a month to be deployed to production environment.
So my task was to add some colour coding to SharePoint Calendar for different event type... in the past, I have done it by creating a calendar webpart using the Calendar control in ASP.Net, which I have full control of the calendar. Due to limited timeline, I turned to Christophe's blog who have published an article on how to style MOSS 2007 calender without deploy a single WSP... and I love it!
Add color coding to your SharePoint 2007 calendar in 15 minutes
Also, check out the HTML Calculated Column: solutions for SP 2010
The biggest benefit of this approach is the quick turn around time for the client, not complex deployment process, my client is welling to negotiate due to some styling limitation, but they love the quick turn around and happy with the result.
Thanks Christophe! you are my hero!