Efficiency of linq expression

Hi,

I have the following method that needs to run as fast as possible (don't
they all).

I hope it is obvious that I want all mobile users and all landline users who
are not in the mobile list.

I sincerelly doubt this is as efficient as it could be.

Maybe somebody can point out a faster way of doing this:

public override List<Callee> CalleesForInitialSend()
{
    var mobile = new List<Callee>(Callees.Where(x => (x is MobileVoiceCallee
)));
    var landLine = new List<Callee>(Callees.Where(x => (x is
LandLineVoiceCallee)));

    mobile.Join
        (
            landLine,
            mob => mob.Contact.Uid,
            land => land.Contact.Uid,
            (m, l) => l
        )
        .ForEach(x => mobile.Remove(x));

        return mobile;
}

===================================
View archives and manage your subscription(s) at http://peach.ease.lsoft.com/archives