There is currently no way of inserting a live hyperlink into an Entourage
message, at least no convenient or straightforward way. You can always
insert the URL, with the http:// prefix, and most email clients should
automatically convert them to active hyperlinks.
An alternative, if you are using Entourage 2004, would be to use Word 2004
to compose your email message, since you can easily create hyperlinks in
that program (select some text, then hit Cmd+K). If Entourage is configured
as your default email client, you can, when you're done, go to File>Send
To>Mail Recipient (as HTML) (this is still in Word, by the way). The
downside to this method is that once the document has been passed on to
Entourage, you can no longer modify it, or add attachments to it.
Yet another alternative would be to use Paul Berkowitz's free AppleScript
Make Hyperlinks X, which you can download here:
<
http://scriptbuilders.net/files/makehyperlinksx2.2.1.html>
You should let Microsoft know that you'd like to see this feature at some
point; click on Help>Send Feedback on Entourage and, well, send your
feedback.