wget runs in background without problem. If you don't want the console messages, just redirect them to /dev/null:
Code:
wget http://something.htm 2> /dev/null &
scp may give some problems if you don't use public/private key authentication for passwordless login. In that case you can run it in foreground, enter the password when prompted and then put it in background using <Ctrl-Z> and bg.
If you run this command on a remote machine through ssh, you can add the nohup command at the beginning of the line, so that the program is immune to hang-up signals when you exit the session:
Code:
nohup wget http://something.htm 2> /dev/null &
