Ask HN: How have you used Amazon SQS successfully?

After reading up on Amazon Simple Queue Service (SQS), I have concerns about how to use it effectively. Ordering is not guaranteed and a read from a queue may sometimes show "empty" when in fact there are more entries to process (apparently has to do with how the data is distributed, per their documentation).

I'm interested in how other hackers have been able to make good use of SQS and possibly overcome these issues?