Google once had a program called Related Links, started in 2006 and then cancelled in 2007. Now they’re reviving the name with a new Google Labs experiment. Google Related Links (II) shows further links from a given domain which are deemed relevant to a particular page the widget is embedded on.
You can adjust the number of links to show, as well as things like gadget layout
The related searches can be disabled (i.e. set to 0 searches)
You can add URLs to a blacklist, i.e. these pages won’t appear in related links
You can define “useless prefixes” and suffixes, that is, strings of text from page titles that won’t be shown
This Google product is invite-only at the moment. You need to drop a mail to email@example.com, stating your Gmail address, domains and roundabout page views per day, and then calmly hope for the best. We also don’t know how long the experiment will be around this time. And then I’m not sure if the “related searches by Google” part of the widget is mandatory or optional… it seems like a way for Google to drive traffic to them, but I find it much less useful.