I'm pretty old school.
To manage my time I just keep a "To Do" list on a small notepad next to my keyboard. I cross stuff off as I get it done and write down new tasks as they come up. When it gets too messy I transfer the uncompleted tasks to the next page and toss the old one.
For tracking sponsors:
• I rely on StatsRemote to keep track of sales, conversion ratios, etc.
• I have categorized folders set up within my bookmarks (favorites) to keep track of sponsor admins and logins*.
• I use an Excel spreadsheet to keep track of payments.
*
I use MozBackup to save my browser profile from time to time. Not only does it save your preferences and bookmarks, it also saves your stored passwords