Clickable links in Blog Comments

[#1]

Please could someone confirm how one should enter a URL in a Blog Comment with the intention
(a) that it becomes a clickable link, and
(b) ditto but hides behind highlighted text.
I discovered the hard way that BBcode tags don't work.
I found this topic from the early days of the beta site (link) but having read through that I am no wiser.
Regards, David

[#2]

Html links work, e.g. <a href="http://www.example.com">example link</a> but since we use bbcode in the forums it would probably make more sense to use bbcode in the comments too. I'll add bbcode to the list of suggested wordpress plugins

[#3]

Thank you; I'm sure this plug-in would improve ease of use for those less familiar with HTML/BBcode subtleties.