Try this, look up hotels that are Historic Hotels, There is a website, but forget what is... But anyhow, many of the historic hotels are part of this group that gives discounts to the other's employees.  Since I am part of the Historic Mission Inn, in Riverside, I can get into places like Wyndam, Sir Francis Drake, etc...  while most of them are not four (most are three) many of them are still cool places to take a chick, since it has so much "character".  In any case, most of these places ask where you are from, check to see if that hotel is part of the list that participates in the discout program, but never really call in to find out if you really work there.  They may ask you fill out this form, but again, they usually don't check it out. 
In all the best cities (and a few of the not so best cities) there should be one or two.  I will try to find the website that lists them all. ... 
Foud it...  Call their reservation desk and ask if they participate in the HHA discount program.  Tell them you are a summer worker from the Historic Mission Inn in Riverside.  Worse come to worse,  if they do need to verify, tell them to call the historic Mission Inn.  PM for my office info and I will vouch for ya...
http://www.historichotels.org/