The Collapsible Wine Bottle
You already know how to sneak booze in anywhere, but here's another trick that borders on the essential: a collapsible wine bottle. Wine2Go is a essentially a BPA-free bladder for your wine, similar to Flask2Go, and made by the same guys, but in a 750-milliliter wine size.
Because why not?
This might be great for sneaking a Pinot into the movie theatre, but this is also a great option for people backpacking or in the outdoors—since when the wine is kicked, the Wine2Go is flat as a plastic bag. It also doesn't shatter, which is great if you've brought more than one Wine2Go and have the dropsies.