Use the following code:
<pre><object type=”text/html” data=”http://www.flickr.com/slideShow/index.gne?user_id=uid@N03&set_id=sid” height=”500″ width=”500″> </object></pre>
where uid is your Flickr user id number and sid is the id number of the set of photos you wish to display. Using the <pre> and </pre> tags prevents WordPress from re-writing your code, as suggested in this post.
Thanks to the following resources:
Note: there may still be problems with this method. I tried to add a second slide show to this post, and now WordPress’s visual editor is messing up. The visual editor dies if you switch from visual to code view and then back to visual. But you can then “Save” or “Save and Continue Editing” and then edit the post again.