Christopher Schneiter over at Luminous Landscape has a very interesting article on taking long exposures at night, extending the tonal range and even using HDR the odd times. I am not a great fan of HDR with all the tone mapping pushed to extremes but the fireworks picture works very well here introducing a whimsical and fun mood to the scene, and almost looking like a giant exploding sunflower.
Read the article at: Luminous Landscape.