Based on a [Social-Bookmark Engine] you're able to filter special tags and filetypes
http://de.lirio.us thats why i called this wiki-entry "playing with rss extension in mediawiki using delirius us rss feed" : i was sure that i wanted to do all this with the open soure clone http://de.lirio.us ;)
here are some rss-feeds you can get from http://del.icio.us/
TODO: ? store information for a longer (time) period in a mysql-table.