From Immunity's page:
Example Use Cases:
Tell SILICA to scan every machine on every wireless network for file shares and download anything of interest to the SILICA device. Then just put it in your suit pocket and walk through your target's office space. Tell SILICA to actively penetrate any machines it can target (with any of Immunity CANVAS's exploits) and have all successfully penetrated machines connect via HTTP/DNS to an external listening port running Immunity CANVAS Professional. Mail SILICA to your target's CEO, then let it turn on and hack anything it can as it sits on their desk. Have SILICA conduct MITM attacks against people on a wireless network. Use SILICA as you would CANVAS on your desktop - just smaller.