These blow up air-cell bags are great for taking with you to wine producing areas where you might buy the odd bottle at tasting rooms. They are easily blown up using a cheap plastic bicycle pump from a pound shop and before they are inflated they take up virtually no room in your luggage. If taking a special bottle to a friend they are just left behind as they are very cheap on ebay. They are bulky when inflated but really do the job better than risking luggage contamination.
On my last trip to the Cape Winelands I bought back 10 bottles that I packed inside a cheap zip up holdall which I checked in, there were no breakages. I have done a test on their strength by putting in a bottle of wine (very cheap) and first dropping it onto my patio from waist height up to a drop from 8 feet all with no damage.