Hey, how do you put a Youtube video in your UG profile blog? (So not just a hyperlink, but really the movie)
so then how do other people do it? I have a friend on my account and he has a Youtube video under his profile.
As far as I can tell you can't put them in your blogs.

What you can do is put them in the 'About Me' section of your profile, which is on your main profile page. To do that, go to your youtube video and underneath there is a part that says "Embed" (some videos may have this disabled) followed by a bar with:

"<object width="425" height="355">..." etc.

in it. Highlight and copy all of the info inside that bar, then go in to My Profile on UG. Under 'User Menu' click 'Edit Profile' then 'About me & Interests'. Paste what you've copied in to the 'About me' section (you'll notice it says "html allowed", that's why videos can be embedded) and click 'Preview "About" Section'. Your video should show up, then you just need to scroll down to the bottom and 'Save Info'.