1. Create new app called gmap

2. Download gmaps.js

3. controllers/default.py

def index():
    from gluon.tools import geocode
    latitude = longtitude = ''
    form=SQLFORM.factory(Field('search'), _class='form-search')
    form.custom.widget.search['_class'] = 'input-long search-query'
    form.custom.submit['_value'] = 'Search'
    form.custom.submit['_class'] = 'btn'
    if form.accepts(request):
        address=form.vars.search
        (latitude, longitude) = geocode(address)
    else:
        (latitude, longitude) = ('','')
    return dict(form=form, latitude=latitude, longitude=longitude)

Note:  There was an issue #855 and just fixed with the Version 2.0.0 (2012-06-17 23:36:32) dev. If you are using the web2py version older than this, make sure to replace the latitude and longitude as follows.

 (longitude, latitude) = geocode(address)

4. views/default/index.html

Replace it with the following.

{{extend 'layout.html'}}
<script src="http://maps.google.com/maps/api/js?sensor=true"></script>
<script src="{{=URL('static','js/gmaps.js')}}"></script>
<div>
{{=form.custom.begin}}
{{=form.custom.widget.search}}{{=form.custom.submit}}
{{=form.custom.end}}
</div>
{{if longitude or latitude:}}
<p>latitude, longtitude: {{=latitude}},{{=longitude}}</p>
<div id="map" style="height:400px;width:800px"></div>
<script>
$(document).ready(function(){
  map = new GMaps({
    div: '#map',
    lat: {{=latitude}},
    lng: {{=longitude}}
  });
   map.addMarker({
    lat: {{=latitude}},
    lng: {{=longitude}},
    title: 'Here!',
    infoWindow: {
        content: '<p>{{=request.vars.search}}</p>'
    }
  });
});
</script>
{{pass}}

5. Result

Type "243 S Wabash Ave, Chicago, IL, USA" and see the result.