Depending on what version of B2 you have you should check out this plugin....
http://plugins.b2evolution.net/index.php/2006/10/10/youtube_plugin

Thanks John, I will try that - should solve the immediate problem!

I did a couple of searches on the forum (probably should of done that before posting) and found a link to a site that was supposed to demonstrate how to enable object/embed tags but the link was broken, is this easily done?

Here is my example of Flash in a B2 post
http://wow-factor.com/index.php/flash_plugin_test
and here is the thread with the required hacks...
http://forums.b2evolution.net/viewtopic.php?t=7818