rs1:PRIMARY> rs.status()
{
        "set" : "rs1",
        "date" : ISODate("2011-05-18T19:31:35Z"),
        "myState" : 1,
        "members" : [
                {
                        "_id" : 0,
                        "name" : "thor:27017",
                        "health" : 1,
                        "state" : 1,
                        "stateStr" : "PRIMARY",
                        "optime" : {
                                "t" : 1305658252000,
                                "i" : 1
                        },
                        "optimeDate" : ISODate("2011-05-17T18:50:52Z"),
                        "self" : true
                },
                {
                        "_id" : 1,
                        "name" : "odin:27017",
                        "health" : 1,
                        "state" : 2,
                        "stateStr" : "SECONDARY",
                        "uptime" : 19599,
                        "optime" : {
                                "t" : 1305658252000,
                                "i" : 1
                        },
                        "optimeDate" : ISODate("2011-05-17T18:50:52Z"),
                        "lastHeartbeat" : ISODate("2011-05-18T19:31:34Z")
                },
                {
                        "_id" : 2,
                        "name" : "straylight:27017",
                        "health" : 0,
                        "state" : 7,
                        "stateStr" : "(not reachable/healthy)",
                        "uptime" : 0,
                        "optime" : {
                                "t" : 0,
                                "i" : 0
                        },
                        "optimeDate" : ISODate("1970-01-01T00:00:00Z"),
                        "lastHeartbeat" : ISODate("2011-05-18T19:20:24Z"),
                        "errmsg" : "still initializing"
                }
        ],
        "ok" : 1
}

Straylight is the arbieter.