perl/bash question - html link out of text

[Vadkan Jozsef]

I don't know how to modify the:

sed -r 's,.*(http://[^ \"$]+).*,<a href=\"\1\">\1</a>,'

command, to not just:
$ echo "test string http://somewhere.uk/ test" | sed -r 's,.*(http://[^
\"$]+).*,<a href=\"\1\">\1</a>,'
<a href="http://somewhere.uk/">http://somewhere.uk/</a>

rather output this:
test string <a href="http://somewhere.uk/">http://somewhere.uk/</a> test


can some perl/bash gods help me? :)