StackExchange sites, and various other site around the 'net, have a nice tag drill-down feature: You can go to a tag page, like https://drupal.stackexchange.com/questions/tagged/views, and then you can select tags from the "related tags" block, and you are sent to a page that filters contents on the union of the two tags. You can do this as many times as you want, and you end up with only content that has all of the tags you've selected. The tags in the "related tags" block are sorted by popularity, and list the number of items tagged.
Is it possible to do this in drupal? How would one go about this? I'm imagining something like a content-view for the tag page, filtered by tags; and then a taxonomy-view for the block, filtered by relationships with contents in the first view. Seems like a bit of a complex mission. Is there a simpler way?