Could you explain what you mean by "banners"?

I don't understand the request

First, please let me say thank you!  This is the best opensource groupware effort out there!

And so I have challenges for you:
1. Banners in the calendar--please add them!  It makes graphically interpreting the calendar much easier, and is a boon to project management
2. Drag and Drop movement of these banner items, indeed, of any calendar event!

I've understood from a number of people that drag and drop is just terribly difficult to implement in a web based calendar.  I always thought it might be doable with a little bit of java, but...theres the challenge!

Beat this one, and you've got something that nobody else has got--and it would be a wonderful feature addition!