FLV Video thumbnail + Thumbnail Gallery with LinkIDs from XML

Let’s say for instance, our XML file:
<videos>
<video linkid=“AK0001” thumb=“http://www.site.com/pathtofile/filename.flv”>
<link>http://www.site.com/pathtofile/filename.flv</link>
</video>
</videos>

Is it possible to use the source flv file as the thumbnail? Or, is it better to create a thumbnail of all the content?

With this said, how would I create the event handler to satisfy when each thumbnail is clicked, it stores it’s linkid in the $_GET variable?

Thank You,
b0gui