can be found at www.machack.com
Despite the name, it has nothing to do with comprimising computer security. In this case, hacking means to fiddle or tweak with a computer to do more with it. The main event behind the convention is the contest, where participants are given the duration of the conference to create a hack (usually a small application or modification to the system that does something never before seen). Hence the confrence's subtitle, "Caffeine and Code".