Never know when you’ll need a bag? Yeah, us neither. Fortunately, the Matador Droplet ($15) can be stuffed into a compact little holder that’ll fit on a keychain. So you’d never be without a bag again. It’s three litres and waterproof—so you could stuff in in your gym bag and use it to keep your sweaty clothes separate from everything else, or take it to the beach for your swimsuit, or stick it on your boat key and break it out to keep your electronics dry. Tonnes of uses, really.