Xumii, a social address book for mobile phones, has closed a round of $5.5 million from CM Capital and Southern Cross Venture Partners and plans to launch today at the DEMOfall 08 conference. The San Mateo, CA and Sydney, Australia-based company’s service lets users socialize with any contact, whether it be from a social net, instant messaging service or another mobile carrier, and share files, post pictures and messages, and utilize mobile messaging.