SecurityTube.net is a new entry in the *tube genre of video aggregation websites.  It specializes in security videos of all types.  While YouTube and other sites have been a great resource for me, SecurityTube has the potential to be so much better.  It is still in beta and new features are being added but its a fully functional site with lots of interesting videos to watch.  The interface is a little bare to be honest but I think they're trying to seperate themselves from the rest of the crowd, but it does need some polishing, there are some features missing (like volume controls).  Also, some of the videos are a bit hard to understand because the speaker is not a native English speaker, but you should be able to understand it enough. 

Here is a sample video about IP packet injection.

The videos are divided into sections labeled Coding, Tools, Basics, and Fun so you should be able to find what you're looking for relatively fast.  The site does have a search feature, of course so if you know exactly what you need, you can find that as well.  Keep in mind that this is a new site, so it needs some people to upload content.  I encourage everyone to do so and help make this site big!