Cleaners. The Ugnaughts of Big Business?

It's struck me that not a lot of positive energy is thrust towards those people that keep our workplace clean and tidy - the Cleaners.
 
I think by many, they are seen as the Ugnaughts of the workplace, that is they work in the background and we take the fruits of their labour for granted.
 
When one is seen in the cold light of day, it's difficult to discern the appropriate response. Do we greet them the same we would a fellow worker, or do we ignore them and hope they'll escape back to the bowels of cloud city?
 
Generally, "The Cleaner" has been used as the butt of many jokes in sitcoms, usually in some sexual manner and usually as an ethnic minority. Seinfeld, for instance, sees George getting fired for having sex on his desk with the office cleaner, while in Andy Richter Controls The Universe, Andy gets Windex in the eye because he didn't call "Consuela".

I find the fact that many office cleaners don't speak English to be a huge stumbling block to fruitful communication, as they must find my lack of Spanish, Portuguese, or whatever non-English language they speak. 
 
Still, I have to say, I'm glad someone else cleans this place, I'd hate the monumental task of cleaning my workpod left up to me, it's messy enough as it is.