[Testing the entry from my forum here]
There is good news and there is bad news. You can include your hosted videos, but it does require a bit of practice.
There are security issues that limit html embeding in the DNN core. You cannot simply cut and paste the embed link from youTube or similiar Flash based sites. In order to display these objects correctly, the user should write their message in the RTE (the editing box), and then select the html view by clicking the Source button in the toolbar. If you are unfamiliar with html, don't worry, you can just scroll to the bottom of the code, paste the embed link from youtube, hit the enter key, and either return to WYSIWYG view by hitting Source and then click on Submit when you are finished. This will enable the forum to process the flash based video link. Note: The video will not display while you are in the editor, a place holder labelled flash will display until you have submitted the entry. For example, the following is a sample of the embed code found on a YouTube page:
"<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/UshWS-1j15c&hl=en"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/UshWS-1j15c&hl=en" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>"
This was entered in the editor. After I switch to html and paste it again:
Now you will actually see the video in the forum. You can also just link to external videos by pasting the URL:
http://www.youtube.com/watch?v=UshWS-1j15c&feature=related
And if you want to make them friendlier, you can type a label, highlight it, and then use the link button on the toolbar:
Camaro on Dyno
Whenever creating link, please select new window as the target.