If there is a wordpress function/feature that I cherish the most, it is the Custom Fields area.

It can be used for almost anything from loading custom style sheets for pages, displaying extra information in your post, to anything. The uses are countless.

I have used it incorporated with embedding video, ratings, and others. So for the first one i will post the embedding video one.

<div id="embedarea" style="display:none; width:640px; float:left; height:100px; padding:0 0 10px 0;">
<textarea name="thoughts" rows=4 style="border:1px solid #B8B8B8; width:642px; background:none; padding:5px; color:#ffffff; font-family:Arial, Helvetica, sans-serif; font-size: 12px; margin-top: 10px; overflow: hidden;">
<embed src="http://www.longtailvideo.com/jw/embed/player.swf"
width="480" height="360"
type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer"
enablejs="true"  allowscriptaccess="always" allowfullscreen="true"
flashvars="file=<?php $key="videoembed"; echo get_post_meta($post->ID, $key, true); ?>" />
</textarea>
</div>

the “embed src” is teh location of the player you will use to play the video that is in the “flashvars custom field location” — JW PLAYER is the one i use - http://www.longtailvideo.com/players/jw-flv-player/

file=<?php $key="videoembed"; echo get_post_meta($post->ID, $key, true); ?>

you will have to put this in the post loop – http://codex.wordpress.org/The_Loop