On your second question,
show some pictures OVER the map near
the city?
I like @andykram's response above, but I've implemented this previously using the Panoramio layer available for the Maps API. It can get a bit crowded but its an interface people are used to and because it is so simple to include it in a map, it just be the solution for you this time.
Just add the following to your map initialisation function.
var myLayer = new GLayer("com.panoramio.all");
map.addOverlay(myLayer);
As far as dynamically showing any city in the world in a Google Map, the solution is easily implemented - you need to geocode the name of the city. This can be done by triggering a function on an event like onclick.
function showAddress(address) {
if (geocoder) {
geocoder.getLatLng(
address,
function(point) {
if (point) {
map.setCenter(point, 13);
var marker = new GMarker(point);
map.addOverlay(marker);
marker.openInfoWindowHtml(address);
}
}
);
}
}
If you hit a hurdle, try this first - http://econym.org.uk/gmap/ - possibly the best resource for the GMaps API on the web.