There's a lot of information by other posters on this topic, and updated listings on which properties have security and when.  A simple search will reveal a lot of information, but beyond that, security is not something to worry about.  In most cases, you just have a wave a card at a security person at the entrance to the elevator bank.  Most of the time they're just standing behind a podium and just give you a smile as you wave your card. In others you have to use your key card to enable the elevators.  A couple actually have you insert the card into a reader at the security desk, but that's rare.  This being Vegas, the elevator banks are usually very busy so you're just another of the thousands of people that pass by security every hour.  Act like you own the place and you'll be fine.  Just be very specific with whoever you're meeting downstairs as to where to meet, and describe what you're wearing.   The only problem I've ever had with someone who I met downstairs was when she asked me "So, what do you do for a living?" in a packed elevator going up to the 54th floor.

you can have fun in the elevator when its packed .. Especially if there is an older couple.   some of the ladies i have met its pretty obvious, no matter what they wear.  Especially the blonde DDD 30 ish girls with me the mid 50s guy .   and of course the wives all notice and make un approving faces to their husbands.  .   so i like to casually say something to the young lady like ..   "so its $4,000 tonight and that includes staying for breakfast?"      one escort I was with could barely keep herself contained from bursting laughing out loud.        i have even waited til there were a few people to join us in the elevator.  

its nice to mess with tourists from Toronto or Kansas    

of course the other extreme is being alone with an escort and giving the security guys watching the cameras a show      

in any case just have fun.   if you look like you are happy the guards wont notice ..  they only notice you if you look nervous.

I must say that given the events of this past weekend security may change their tactics soon

But many hotels dont have it and those who do you just flash your room key as you stroll by the podium the guard is at.