Most of my tasks actually begin as emails in my Inbox.  Normally I add these emails to my task list by using "Move to Folder".  Outlook 2010 has given me another option.  There is a new feature called "Quick Steps" and you have the ability to customize a step to meet your needs.  I recently created a step called "Create a task".
Locate the Quick Steps in the main ribbon.
- Use the pull down arrow to find MANAGE QUICK STEPS
- Select NEW and then CUSTOM
- In NAME,  I typed "Create a task "
- In CHOOSE ACTION, scroll until you see CATEGORIES, TASKS, and FLAGS
- Choose CREATE A TASK WITH ATTACHMENT
- Select FINISH and then OK
Now when an email arrives that needs to be added to my task list, I  highlight it and choose my new quick step.  If you find yourself repeating the same action over and over again, such as filing an email into a certain folder, be sure to take a look at Quick Steps.