You will need to install a user script manager extension to install this script.
This moves the "Contact this Requester" link on your status detail pages (where it lists all the HITs you've done for a day) to a little mail icon next to the requester name, and makes their name a link to a search page for their requester ID. This will let you easily find HITs by requesters you know you like, while still being able to contact them about a specific HIT. I don't know why this wasn't already a feature of the site.
Please let me know how I can make this better or more usable!