I did i like this:

dojo.connect(featureLayer, "onUpdateEnd", function() {
        var defaultSymbol = new esri.symbol.SimpleMarkerSymbol().setColor(new dojo.Color([0,0,255]));
        dojo.forEach(this.graphics, function(graphic){
                graphic.setSymbol(defaultSymbol);
            });
});

Yet I'm not satisfied with this solution because when I add new features to the layer they are added with default symbol (black circle). Do you know how to set up symbols for the layer once and forever?

I did this:

dojo.connect(featureLayer, "onUpdateEnd", function() {
        var defaultSymbol = new esri.symbol.SimpleMarkerSymbol().setColor(new dojo.Color([0,0,255]));
        dojo.forEach(this.graphics, function(graphic){
                graphic.setSymbol(defaultSymbol);
            });
});

I'm not satisfied with this solution because when I add new features to the layer they are added with a default symbol (black circle). Do you know how to set up symbols for the layer once and for all?