It kinda gets on my nerves when musicians do this. I'm sure the first time it was done it was totally cool, I can see that happening when people just think "Wtf all this silence! Misprinted CD?" and skip ahead on it but seriously, who doesn't just blank out and leave it running without even realizing? So even if it was cool the first time it's really boring and old now, as well as being entirely obvious.
No more 'hidden' tracks if you musicians please.
Edit: And hahahahahaha I just saw what Lunar said that's legendary xDDD