I am always trying to keep a list of accomplishments and tasks and just ran across a great free one thanks to Lifehacker named QuickLogger. It simply logs a task and timestamps it in an excel spreadsheet. It can automatically rotate each week starting a new file so you have a continues archive. You could use it just to have a list for keeping track of what you do for later review or for use in year in review performance and accomplishment reports.
Now if it only had a To Do list option combined I would be set and not have to jump in and out of Outlook.