We all know those silly questions that we are asked upon checking into the airport:
"did you pack your own bags"
"has anyone unknown to you asked you to carry anything onboard"
"has the bag been out of your possession" etc.
I'm sure those questions will really trip up a criminal or terrorist (insert sarcasm here).

So here's my question: Hotel check-out is 12PM. Flight isn't until 8PM. The hotel offers to hold my bags until it's time to leave. . . . . Gate agent asks her silly little questions. "Has this bag been out of your possession since you packed it?"
Now I am a law-abiding citizen with no intention of commiting any sort of crime, least of all to a plane that I'll be riding on. I want to answer truthfully, but that might mean more questions, hassle, and pissed off people behind me waiting to check in. I don't like lying but sometimes it is just easier than going through the explanation of where my bags have been for the last 8 hours.

What do you do? What should I have done?

When you pick up your bag from the hotel take a peak inside to make sure everything is still as you left it. Nothing added or subtracted. Then you can answer truthfully.

Suzie's answer is the most sensible.
I once asked an agent "Now come on, who is really going to say "Yes, I'm carrying things I didn't pack"", etc, etc. She informed me that there actually are cases where the questions are useful. One is when professional couriers carry items with them.
But the simple answer to your question is: what suzie said.

These questions aren't designed to trip up a terrorist, but to catch DUPES of terrorists. The trick works like this, and is not limited to bombs (sometimes done with drugs or other contraband):

Person trying to get something illegal on a plane comes up to person with a small amount of luggage. Charms the person. Tells sob story about being every so slightly over weight limit for a package going to the same place victim is going to. Pleads EVER so nicely to allow this small item to go with your luggage, even offering to pay.

I remember being puzzled the first time I heard these questions, until this scam was explained to me. Now I understand and I have no problem with them.

After the hotel stored my bags, I answered the question truthfully and the ticket agent got mad at me. He explained that if I answered 'yes' to the bags being out of my possession, he was going to have to chase after the bag he had already sent down the conveyor belt and it would have to be unpacked and examined. Luckily no one was behind me and I sheepishly answered the way he wanted me to and he didn't have to go get my bag.

I think the poster who suggested looking inside your bag after it's been in hotel storage was smart. I'll do that next time.

Whether or not you look inside the bag after retrieving it from the bellman, the answer to "Have your bags been out of your possession...?" question is still "Yes."

Not if you want to get on the plane without hassle.

Ok, if you must be absolutely literal, move things about and consider it repacking. There. The bags haven't been out of your possession since packing.