This is terrible for SNL's, but it works in the long run. The idea came from watching this old film noir about a botched diamond heist. The mastermind behind the whole thing is trying to flee to Mexico, but first he's got to make it across town without being caught by all the cops looking for him, and his wanted mugshot in every newspaper. Someone offers him a gun, and he declines. His logic is that if you carry a gun, you're more likely to shot someone -- a cop maybe -- then you're up for murder. And if you shoot a cop, chances are they'll kill you.
There's a similar mentality behind my tactic of never carrying a condom. If you carry a condom, you obviously intend to fuck someone. I'm not sure about everyone here, but I always try to practice safe sex, and I always try to use a condom the first time I'm with a woman at least. Because I never carry a condom, in the final stages of seduction, I can always say, "I don't want to have sex because I don't have a condom," then I continue plowing through. This is pretty great form of plausible deniability, escpecially if you actually mean it. Every time I've done it, it allowed me to go pretty far with the girl just without any actual penis/vagina intercourse. The last time I did it, the girl asked me why I didn't bring a condom (note hours earlier she was telling me she wasn't going to have sex, because it would be weird fucking on the first date). I told her I didn't think we were going to have sex. It makes it seem as if the whole thing "just happened." The next time you see the girl, she's sure to want to have sex. Or if you go to her place and she keeps condoms herself, she might break them out and offer them to you.
I was curious what you guys thought. I've tried it a bunch of times and it has always worked for me. It is the long way of going about things (usually calls for a day 2 or even 3) but it's been a sure way for me.