I don't believe anything but videos have the capability of being sent via HDMI to your tv on the Droid X.
When you are playing a video on you stock video player, a little HDMI button should appear in the upper left hand corner of your screen. If you press it, the video will be transferred to your TV and just a control panel(play, pause, etc...) will appear on your phone screen.
Thanks to rcschnoor for that information!
This information is coming from the Droid X User Manual (Page 23)http://bit.ly/P4YcUe
Note: You can view only user-generated content—your
own photos and recorded videos. You cannot view
commercial content—photos or videos that you
purchased and downloaded
1. To select an HDMI format, press Menu>Settings>HDMI.
2. Connect an HDMI cable from the HDMI port on your
phone (see “Your phone” on page 2) to an HDMI
port on the TV monitor.
3. Touch Launcher icon >Media Share > Start> Television> Play.
I'm sure this helps!
Follow us on Twitter @VZWSupport