Nine times out of ten I can spot them. We were once at a Starbucks having coffee around 11:30 a.m. on a Saturday and this woman in a skirt was with an older woman and I said to my boyfriend -- "they are dubs" and he was skeptical. So I casually listed to their conversation and that confirmed it (meetings, sister, brother, etc.).
They are easier to spot on the weekends -- other than that, I do not easily spot them in a crowd.
Purza