Just thought I'd add 2 cents about the "unwaterproof" mini Bics. What I do with all my Bics that are in kits is put a tight rubber cap over the important end; keeps water/dust out and might even prevent accidental gas release by lever getting pressed.

These rubber caps are the things you put on your fingertips for paper handling. No. 2 (typ. yellow) is perfect for a regular Bic, No. 00 (typ. red) is right for the mini Bic. Stationery/dollar stores, very cheap for a pack, other odd-ball uses.

The DX ones don't have a flat bottom, they have a rounded lanyard loop. I just got back from an overnight trip to a local state park where I played with the lighters a bit. Overall they worked just fine but are pretty vulnerable to wind.

They're very small and easy to keep on one's person, so I do like that, but for the strength of the flame I'd give the nod to the mini-Bic. I will probably keep using them both.

I was wondering if the lighter in CAL's link has a flat bottom.

Regarding the issue of wind, that's another important consideration of course! I have found that even a Bic is difficult in a moderate wind. There's no replacement for testing gear. It exposes issues one may not have otherwise considered!

Pheadrus, 'o' ring disappeared, got lost, under night time zero light, outdoor, in the woods test conditions. The 'o'ring on mine were very loose once you opened the lighter.

Ireckon, No it does not. They did not have this one http://edcdepot.com/spycapsulelighterwflatbottom.aspx when I bought mine. If I had seen this one, I would have purchased it. It is the same price as the one with the round bottom.