Multi-tools definitely are useful, but not everyone likes jamming the things down into a pocket. That's not a problem with the titanium-bodied K-Smart, since it doubles as a clip-on chainring which can be quickly removed as needed.
The Ultimate 11-in-1 Titanium Multi-Function Keychain by Ideaspark — Kickstarter
Titanium multi-tool adds extra functionality to the humble keychain
EXTREMELY FUNCTIONAL - 8 Tools in 1 Key-Shaped Key Chain Multi-Tool Including a Flat Head Screwdriver, 3 Wrenches, Bottle Opener, Box Opener and Hex
Lunamax Mighty Key-TITANIUM 8 in 1 Multi-Tool for Keychain- Strong, Lightweight, All- in-One Bottle Opener, Flathead Screwdriver, Wrench, Box Cutter
Keychains
Valtcan Titanium Carabiner Multi Tool Key Chain Holder Glossy Stonewas
Titanium multi-tool adds extra functionality to the humble keychain
Titanium keychain tool,Lightweight Multipurpose Tool, Paint Can Opener, Pry Tools, Wrench Bottle Opener,Ideal Every Day Carry for Men
Keychains
11-In-1 Titanium Multi-Function Quick-Release Keychain by Ideaspark — Kickstarter
Titanium Multi-Tool Key