I first spotted a carabiner mug clipped to a stranger’s pack at a social gathering in the woods. When I ran across the same mugs in a hardware store later, I picked one up. You can find them around the internet for less than 8 or 9 bucks. I don’t recall what I paid for mine, but I believe it was even less.
The cup is simply a stainless steel double layer (air inbetween the layers) cup with a carabiner attached to the side. I’ve seen some with the carabiner soldiered on, but mine was attached using two small screws.
I frequently clip my cup to my packs for both urban and primitive trips. I’ve sipped morning coffee from my cup more than once. I also found another extremely useful place for this cup – Burning Man and related gatherings. Oftne times, at these events, folks provide free beverages; however, you’re expected to bring a cup.
The carabiner itself can be pretty useful. If you find yourself needing one more carabiner to clip something to your pack with – just use your cup! It seems like such a simple little solution, and it is… but wow, I’ve found it very useful.