Onlydarksets

ToodleDo Sync Tool – syncs Outlook to ToodleDo (which, in turn, syncs with a bunch of iPhone apps)

For Outlook 2003: ToodleDo causes Outlook to give a security prompt. Advanced Security for Outlook by MapiLabs lets you get around that.

If you are in an environment where you don’t have admin rights to your PC, you can Express Click-Eyes, which is a less-elegant solution, but equally effective (it doesn’t bypass the security screen – it checks the box and clicks “Yes” for you).

Also, LifeHacker posted a list of Outlook add-ons.  There are some interesting solutions on there, but nothing that interested me.