I'm really liking Siri for two things - reminders and text messaging. I'm not in the habit of wearing my bluetooth headset all the time, but I'm finding it very convenient to wear it while I work, so I can tap it and use Siri to set a reminder or send a text. The reminders sync to iCloud, so I get them within a couple of minutes on my ipad.
The one problem with messaging is that you can SEND without picking up your phone, but there's no way to have replies read to you. So you end up having to have the phone at hand anyway. That kind of kills the usefulness for texting while driving.
It's also useful for cooking - throw something in the oven and "Set timer for 10 minutes", instead of wondering where the kids put the kitchen timer this time.
