We're going travelling soon and we wanted more security to our hotel room or our overnight train cabins. I first saw the Add-A-Lock on Amazon but it was decidedly too expensive and plastic. Then I found this Qicklock which looks like an Australian company which offers a full steel version at a list price already half of the add-a-lock.
Just got it in the mail today, tested it out and seems to work quite well on most locks (except one of my doors that has a bigger lock which probably won't need it anyway). It's got a credit-card sized profile but about 1cm thick when stored in its own pouch so I think it's quite good to travel with. I'm always impressed by these simple but amazeballs effective little inventions. Especially if it's the brainchild of local Aussie geniuses.
But anyway, along with the "Thank you" letter that came in the same envelope was a 50% off promo code for my next purchase which brings it down to just $5!!! So I thought I'd share that with anyone who's either travelling soon or just want to add a lock to their room to block out pestering family members etc or whatever :) Enjoy!