Twitterfeed was so easy to use! You just enter a couple of pieces of information and BAM! You have some instant content into your Twitter account. This completely automates the notification of any new posts on my blog. Plus I get some additional content in my Twitter. Very Simple. I would also recommend TweetLater and twhirl.
The OpenId thing was a little new to me, but easy. I already had one with my WendyMerritt/WordPress and didn't even know it!