I recompiled flickr for 2.0.34, and added a "tag search" feature.
From the README:
To make flickr use tags, create a file in the same directory as your flickr.roku program, and include a single line, like this:
You can have as many or as few comma-separated tags as you like. No spaces!
Then run flickr. In theory, it will read your file and apply your tags to the search.
Note that it could take as long as five minutes for flickr to download the entire list of tags... don't go hitting buttons or running other programs while you're waiting for flickr to start!