Barking is in my job description; it's what we terriers do. I Offenbach at mailmen.
There is a common mis-conception that the purpose of barking at delivery people is to chase them away. We terriers bark in order to inform our humans that they have guests (it's also a lot of fun).
Most xylophones are made of wood, but here is one made of bark. I practiced to bark each note on key. Click on the notes, one at a time, to download the sound files. Then, you can click on the notes in sequence for a tune. You too can play the opening to "Been Caught Stealing"
Biff, the Unix wonder dog, developed the concept of barking at e-mail. Unfortunately, the wave files usually assigned to this task are a dull, spoken, "you have mail". Wouldn't it be nice to have something more appropriate? Just right-click on the word "appropriate" to save the wave file on your computer. Then go to your control pannel, select sounds, and associate "New-Mail-Notification" with the saved file. Once you do that, the boring announcement will be replaced by my bark each time you get new mail.
Microsoft has offered to send me a developers' pack for including .WAV audio content. Then I get a real excuse to bark at the mailman (yay!)
My neighibor, the G-Man, has a whole collection of e-mail sounds.