I just saw this tip on Lifehacker which points to a Tech-Recipes post on how you can customize your Outlook Today with just a bit of HTML code. Their post offers up some HTML templates for the various Outlook elements like Inbox, Calendar, Tasks, Contacts, and Notes.
But I also have to point to this TechRepublic post which gives some more details on this process, including the how-tos on how to extract the HTML page and the graphics in order to tweak them.
Pretty cool stuff. I did this once when I was bored at work and gave my Outlook Today page a pretty pale pink and purple swirly background. It rocked, of course. Have you ever customized your Outlook Today?