Gil-Tek RUK Utility Knife
The RUK, or Rapid Utility Knife, comes from Gil-Tek, a family run business out of Colorado. Its design is based on the owner's own daily carry needs, which typically don't require the entire edge of a blade but, as it were, just the tip. So the RUK takes some desirable features of a full pocket knife - namely a one-handed operation - and applies them to standard utility blades and a unique sliding casing.
RUK blade access comes via a mechanism similar to those on sliding USB flash drives, except it also locks the blade in both its extended and retracted positions. And for times you're more interested in guzzling than cutting, standard RUK knives also have a bottle opener built into their ends.
Gil-Tek's RUK V2, available in anodized aluminum or titanium, adds a few other tools to its finger-sized footprint: a pry bar / screwdriver on the end; a fishing line / string cutting opening; and a 1/4" hex for driver bits.
Muchas danke to Manny for the Dude Product Tip.