I visited my mother this weekend in Idaho and found her wireless unsecured and changed it. My suggestions at the very least are to change the router name, enable WEP, and do not broadcast you SSID to your neighbors or those within range.
I also had my oldest son with me who recently got his learners permit to drive (Ugh). I let him drive most of the way back from Idaho and while he did fine and safe there were a few white knuckle incidents for me being overly sensitive. He has to log 100 hours of driving with me before he can get his license. I feel so old.