If you frequent any of the bigger blogs lately, you will notice a new trend that is emerging in the WordPress sites: toolbars & notification bars. With the biggest blogs (such as the new notification bar on Problogger) the most popular option seems to be A/B split testing with the HelloBar.
However, this is far from the only option, and in many instances may not be the best option for your blog or what you are trying to accomplish with your notification bar. This is a real key with what notifaction/toolbar plugin that you should choose: clearly define what you are trying to accomplish.
Are you trying to navigate visitors to a “Start Here” page? Are you trying to build ‘Likes’ and more followers on your social networks? Are you promoting a new product of yours? Are you letting visitors know of new projects in the works? These are important questions to ask and answer before you install a notification bar at all, let alone choose a specific option.
So let’s look at some of the better offerings out there, and what they seem to be best used for (from other reviews and my own experiences).