CS: The Customer Is Never Right! is a site that has stories from the service industry. I had expected more "funny stuff" and less bitterness, but it's worth a look all the same. Another site that more effecievely combines bitterness and humor would be
Work Haiku.com which has some pretty funny Haiku poems like these:
Is this my life now
This job is just meaningless
Where's my razor blades
It's a dead-end job
Someone has got to do it
"But, why me!" I cry
Wasting all my time
Selling overpriced rubbish
Wish I could go home
sex is fulfilling
but work is not fulfilling
so have lets of sex