We have all seen and marveled as the simplicity and utility of an Atwood tool. I really liked mine, but it was so expensive I was always worried about losing it. Eventually I settled on a Gerber Shard, which I like quite a bit. If you want something a bit more craftsmen-y, but not as hard to get as an Atwood, there are bunch of makers out there. Here is an overview of them. But a new maker with really interesting designs just started making stuff. Check out TT PockeTTools when you get a chance. His most full featured OPMT, the TT Chopper, is seen here:

It is only $26, a reasonable size for a keychain, and made of S30V. Check, check, and check. Definitely a nice alternative to an Atwood and a welcome addition to an interesting market niche. The picture is taken from PockeTTool's blog as there are no images out there other than this one. Hope he doesn't mind.