You should keep it to yourselves if smoking where they aint too cool about it - from a distance a J looks no differant to a ciggie, however - the act of passin it back and forth shows that it's a joint really,

if its somewhere that really is harsh against weed or if im in public i either make a secret agent (empty out a cigarette, and replace the filter with a roach) and I use kiff/keef with tobacco, that way there isn'tany particularly incriminating smell,
Or Simply cut off the orange paper from a cig butt and wrap it round the bottom of your roach, jus means it won't look as obvious on first glance as a long white cone!

Jonny