When I visit http://maps.google.com on my iOS device, the current location is shown as in the image below.

I’m creating my own Map using the Google Maps API v3. How can I create this function?
I’ve tried their sample using geolocation in the web browser but it just displays an text box on my location. I would like it to be similar to the image above, where is it shown using the blue markers and a circle showing the accuracy. Is this default behavior if Google Maps API v3 or should I design it myself using an icon, marker and circle?
You can set the marker image by setting the icon property of the MarkerOptions object passed into the Marker constructor to show a custom image.
http://code.google.com/intl/da/apis/maps/documentation/javascript/reference.html#MarkerOptions
Here is a site with some more information about using Google Maps API V3 http://www.svennerberg.com/tag/google-maps-api-3/