Three good videos on Javascript theory by Douglas Crockford (Yahoo Javascript expert)

http://yuiblog.com/blog/2006/10/20/video-crockford-domtheory/

Some neat tidbits here; for example, why

<script></script>

is preferable to

<script language="javascript" type="text/javascript"></script>

(language is deprecated by the W3C; and the usual mime-type is incorrect – strictly speaking it should be application/javascript or application/ecmascript).