It’s hard to say if netbooks are completely to thank (we’re guessing they only deserve some of the credit), but mobile broadband is booming. And when we say “booming,” we mean “93% year-on-year growth.” According to Informa Telecoms & Media’s latest World Cellular Data Metrics report, which takes a close look at non-voice mobile revenues and usage, there were over 225 million mobile broadband subscribers across all technologies (3G, 4G, WiMax, HSUPA, etc.) at the end of March ’09, which represents a staggering