Today is the day that all of us existing iPhone owners will be able to upgrade to the iPhone 3.0 OS. I waited up until midnight last night with a bit of hope that Apple would turn on the update just as we pased midnight Pacific time, but that didn't happen. The talk around the Internet is that the update should go live at 10:00 am Pacific Daylight Time. In the meantime, to get you prepped on what to expect with your 3.0 update The iPhone Blog put together a detailed iPhone 3.0 software walk through that I highly recommend you check out.
One added feature of the iPhone 3.0 update that I have been looking forward to is the support for A2DP stereo Bluetooth headsets and The iPhone Blog also has a great Bluetooth stereo iPhone 3.0 roundup that takes a look at four different headset solutions for you to consider.