Amazon URL shortening

A friend who used to work at Amazon gave me at tip about how to shorten their URLs.

For example, here is a standard URL to an Amazon item:

https://www.amazon.com/exec/obidos/ASIN/B0000ALFVD/ref=amb_center-3_6699/002-8270699-8637653

To browse to the item, you don't need the last two portions of the url, the /ref=...
part. So if you want to have a shorter URL for sending around, you can just send this
part:

https://www.amazon.com/exec/obidos/ASIN/B0000ALFVD

This satisfies the obsessive-compulsive part of my brain immensely.