I don't know about other places, but here 9in Vegas, the people who take 
me from the counter through security and to the gate do expect tips.  The 
air lines people who help me board the plane don't though.  I had one 
doofus guy ask me all kinds of questions.  Did I have a wife, why didn't 
she take me to the gate, did she give me money for tips and so forth.  How 
much I tip depends on how nice the people are and what kind of service I 
get.  Here in Vegas, almost every one expects a tip.  Cab drivers 
certainly do, and I usually tip ten to 15 percent.  I've never had anyone 
refuse a tip.
73
Butch Bussen
wa0vjr
open Node 3148
Las Vegas