wrap anchor tags around links in the database

[eluser]brian88[/eluser]
Say I have a input field named "bodyText"

users enter something like this into the input field, "Hey check out this awesome link http://www.kickasshumor.com"

Now how can I wrap <a> tags around it to make it look like this when it gets inserted into the database?

Code:

Hey check out this awesome link <a href="http://www.kickasshumor.com">http://www.kickasshumor.com</a>

And is it possible to tell if the link is from youtube, then just embed that youtube link on my page?