I know you have a small amount of control over the Dashboard Widgets, however, they are limited in what my management wants to see.
I've been looking to see if I can edit the Ticket Chart Widget in some way. Right now it's only show the top x (10) open items for a user. When you click the link though it takes you to the advanced search query page, and it has injected a is X in the last 4 weeks option to an already created search query.
When you view he query it's right. I would love to find a way to make a widget behave how I'd like. Right now the options for Widgets and the functionality make them a novelty and not very useful.