flickrSLiDR allows you to easily embed flickr slideshows on your website or blog. All you need to do is enter the flickr URL address of the user, photo set or group you would like to embed along with some options. You'll receive the HTML embed code in return.
Flickr slideshows do not work on MySpace and LiveJournal due to the restrictions placed on these websites, sorry. Also, if you use WordPress.com there have been reports that slideshows cannot be embedded, however they embed fine with regular WordPress installations.