Well if you are running windows you can use neotrace like blueline said or you can just open dos prompt and type tracert ipyouwanttraced. To find out what isp they are using go to the following links:

American Registry for Internet Numbers: www.arin.net
Reseaux IP Europeens:www.ripe.net
Network Solutions:www.networksolutions.com
Asia Pacific Network Information Center:www.apnic.net