Shockingly enough, a UBI has been a libertarian concept for nearly half a century. If UBI had some reasonable limitations, like say 10% of the GDP divided evenly amoungst those who apply, it would provide a hard bottom to poverty while leaving huge incentives to find gainful employment.

I'm not saying it wouldn't quickly turn into 51% of the people voting themselves 100% of the money (which would quickly become worth nothing), but it isn't the worst idea out there.