Speed

http://dyn.com/open-dialogue/dynamic-discourse/dns/educational/how-we-got-dyndns-com-to-load-faster-and-how-you-can-learn-from-it the subj. how to optimize webpage load speed by compressing, optimizing images, js, css

http://www.mysqlperformanceblog.com/2006/08/09/cache-performance-comparison/ gives you an idea how different caching methods perform. Read it before implementing something