Watch out for non-ASCII characters in the CLI commands above. That emdash should actually be a hyphen. It got changed to an emdash by software too smart for its own good. Also the first sudo is unnecessary and makes it necessary to type in the password twice, and this may not work.

Next time better blog your commands into a literal text box.

wget -O – http://deb.opera.com/archive.key | sudo apt-key add -

@ubuntu904
Use “sid”. All recent Ubuntu versions will use “sid”.

I did:
sudo wget -O – http://deb.opera.com/archive.key | sudo apt-key add -

and it seems to work fine now.

re: Step 3.
I did ~$ sudo wget -O – http://deb.opera.com/archive.key | sudo apt-key add -

but I see this:
–2009-07-02 00:40:07– http://deb.opera.com/archive.key
Resolving deb.opera.com… 195.189.143.183
Connecting to deb.opera.com|195.189.143.183|:80… connected.
HTTP request sent, awaiting response… 200 OK
Length: 1742 (1.7K) [application/pgp-keys]
Saving to: `–’

100%[======================================>] 1,742 –.-K/s in 0s

2009-07-02 00:40:07 (4.42 MB/s) – `–’ saved [1742/1742]

gpg: no valid OpenPGP data found.

I’m using ubunt 9.04. Which Debian version should I use? Or I should back up and ask, can a ubuntu 9.04 use one of the deb repos?