If you take a look in the theme area of your control panel, you'll notice there's a new official theme available called Resolve. I just finished this up and am really happy with the result. Resolve has a clean and professional style that will make your website look great, and will work especially well for those interested in prominently displaying your latest tweet. Your site image, headline and latest tweet are all displayed above the nav, and a nice graphical background opens up if you use a featured content slider.
Resolve is currently available in blue, graphite, orange, olive green, and red green and black. There are also several font variations, including the beautiful Lobster script, which is also now available for those creating custom themes using the NationBuilder TypeKit.