If it isn't too much of a hassle, it would be fun to see how much of a cigarette/cigar/joint/etc. is left when you look at it.
lo cig
It's lit and it's barely been smoked.
It isn't lit and it's about half smoked.
It's lit and it's just about done.
Could lead to more roach RP, people chucking half-smoked cigarettes and such. Less surprise 'hey you wanna hit this?' sure, oops sorry it's gone. And more openings for people to be snobs about hitting half-dead joints or whatever.