Perhaps what KwangJin So wants is not a greater number of results, but
"more" results for a certain area. In that case, you just need to
reduce the bounds (or location/radius) in the Place Search Request.
http://code.google.com/apis/maps/documentation/javascript/places.html#place_search_requests
You will still get no more than 20 results, but they will be
concentrated in a smaller area (and therefore have finer
"granularity.")
If you want to find a coffee shop in Mountain View, it is better to
specify a tight bounds (encompassing only Mountain View) rather than
one that encompasses all of California.
- Jeff