1. Microsoft OneNote
I use this just as it was intended, as my notebook. My binder is full of everything I need to know to direct the projects I own. This great little Microsoft tool provides the ability to create tabs (Sections) in my binder. I have a tab for each project. And, just like a physical binder I can add pages to each tabbed section. On these pages I can write, paste, insert links or documents or emails, anywhere. I can create tasks which are linked to Outlook with all the reminders and features Outlook provides. I keep track of sprint schedules by team. I then create a page for each team's sprint commitments and update these as the ScrumMaster sends out daily statuses or from I learn in daily scrums. I used to carry around a physical binder with all this stuff, I'm now saving the lives of so many trees.
2. Microsoft Excel
Given most of my current projects area based on reporting solutions we write the details of most of our user stories in Excel. We are a reporting solution provider so often our user stories deal with defining tables and charts which, when it comes to defining Acceptance Criteria, just don't fit on a 3x5 card (although I personally keep epic story cards for user story mapping). We simply add a link to the Excel story from the Product Backlog item.
3. Axure RP Pro
To accompany our user stories or when we are scoping out a project, this wireframe and prototyping application is amazing. A WYSIWYG / drag & drop editor with event handling is great for creating a 'functioning' wireframe or product prototype. This increases more accuracy when the teams are estimating against the user stories. It can also provide that high level view of the product. (Axure RP)
4. SharePoint Portal
When it comes to a central area for our Product Backlog or knowledge sharing, SharePoint has been the solution for us. It's central and accessible by all 3 roles of Scrum. I'm on our portal all day long.
5. Google Docs
Similar to the way SharePoint provides that central and sharable solution for a Product Backlog or Knowledgebase, Google Docs provides that same functionality with the added feature that mutliple users can be accessing our planning spreadsheet at the same time. This is great for planning day as well as estimating sessions.
Having a set of tools to increase my productivity is so necessary for the way my brain seems to work.