Show tooltip on hover of custom marker

I have the following Google Map test: http://jsfiddle.net/gM6Z6/

As you can see it gets your position and then shows it on the map using three markers.

What I want to do is when a user hovers over any of the three markers, I want to show the following tooltip NEXT to the marker avatar:

var tooltipOptions={
    marker:marker,
    content: "You're here!",
    cssClass:'tooltip'
};
var tooltip = new Tooltip(tooltipOptions);

I'm not sure how to best do this, as I need this to work for all three markers, and be in the same position regardless of which marker was hovered. It should ALWAYS appear next to the avatar like in the foursquare screenshot below BUT should move to the left or right dependant on the position of the icon on screen to allow it to fit.

Can anyone help? As the docs are a little vague for my liking on this... I can create the tooltip but I'm confused how best to show it for all three markers but in the same position and viewport aware.