Here is a link to time the ISI time standards.
http://www.ilswim.org/standards/index.htm
Motivational Times for USA Swimming
This is used to find out if your times are a "B" swimmer or all the way up to an "AAAA" swimmer compare yourself to all swimmers in America
If you want to see how you rank among other swimmers across the country
http://www.usaswimming.org/USASWeb/DesktopDefault.aspx?TabId=82&Alias=Rainbow&Lang=en