Does anyone know if something like this is possible? Do a quick search, using tags, for public flickr images, but without using an api ley, and retrieve images based on that search? (I already read Why do I need a flickr API key, I want to know if there are libs that can do this search without it). Or maybe give a rss for a set, and have a list/dictflickr object of the images...
Sure, seduce a developer on the Flickr dev team and get them to open a back door for you. Or use your mad hax0r skills to do the same, sans seduction.
Seriously, though, Flickr says you need an API key to use their API. So you get an API key.
Or you could scrape the entire flickr site, building up your own metadata on the site. The compute and storage budget might be excessive.