<users>
<user>
<id>20</id>
<name>Evan Williams</name>
<screen_name>ev</screen_name>
<location>San Francisco, CA, US</location>
<description>Co-founder and CPO of Twitter</description>
<profile_image_url>
http://s3.amazonaws.com/twitter_production/profile_images/14019652/ev-sky_normal.jpg
</profile_image_url>
<url>http://evhead.com</url>
<protected>false</protected>
<followers_count>14430</followers_count>
<status>
<created_at>Wed Jun 25 20:49:44 +0000 2008</created_at>
<id>843603299</id>
<text>Drinking an Odwalla "Mental Energy Juice Drink." So, um, watch out.</text>
<source><a>txt</a></source>
<truncated>false</truncated>
<in_reply_to_status_id>
<in_reply_to_user_id>
<favorited>false</favorited>
</status>
</user>
</users>
Using (xml-parse) on the above XML, what would be the best way to extract a single TEXT from the ELEMENT "screen_name"? Suppose that a list of users was used in place of the above single user; how would you guys go about populating another list with only the screen names?