However, make sure you look at the fine print before handing over your confirmed seat. I have heard horror stories from friends that have willingly given up their seats only to find their trip a complete disaster.
Always be aware of the weather before giving up your seat...Many savy travelers will try to get on earlier flights because they see the wave of airport closures coming, and want to get out of town. The person giving up their seat end up rebooked on a later flight, but that flight gets cancelled or delayed, potentially forcing you to spend money on another hotel room or an incredibly uncomfortable night on an airport bench.
Make sure your checked bags are actually on the eariler plane. This isn't such a big deal when you're coming home, because most people have everything they need at home. However, if you're just starting your vacation, it's probably pretty important to have your bags when you arrive at the airport. Some airlines don't bother juggling bags, and will simply leave your checked luggage on your original plane. That means you can typically pick them up at the bag claim storage area. However, a few airlines, depending upon when you change your flight, will pull bags to put on the plane that you're flying. That significantly increases the likelyhood that your bag will get lost or get put onto the wrong plane. That's not so bad for those of us that travel relatively light, but for those with kids that can't live without certain items that may be in those checked bags, you could end up with a terrible start to your vacation.
Beware of the fine print on airline vouchers. Some airlines offer coupons that are the same as cash with very few restrictions. Others offer blanket round trip vouchers that are good on any flight in the continental US, which can have far more restrictions. As we found with the United vouchers that we got from getting bumped on our Las Vegas trip, we could get on pretty much any flight we wanted (we were booked 4 months in advance), but the voucher had to be physically redeemed at an airport counter, which meant a specific trip to book our flight. That was 5 years, ago, so perhaps things have changed, but it was something we did not factor in when we volunteered to get bumped. Almost all vouchers are going to prohibit flying around holidays (primarily Thanksgiving and Christmas), and will restrict travel to certain regions during certain times of the year (think New Orleans during Mardis Gras). Finally, all vouchers have expiration dates, so if you have absolutely no way to take another vacation within the next 12 months, don't allow yourself to be bumped.
Well I jumped on that and wound up using the free RT to go to LA which saved me about $600. I had a year to make a reservation with the voucher and could take up to a year to travel after that so I wound up going to LA about 18 months after my original bump.
It's easier when traveling by yourself or with other adults, I felt bad for the families with small kids who were so stressed out. The one thing about living in Orlando is that there are so many people coming down here that your chances are pretty good to get bumped.