I'm a sign student from California, learning in California. It seems like in both the hearing and deaf population of the U.S, California starts a lot of the new "slang", much of which later becomes legitimate words, though with deaf I would assume there is a lot of slang started in DC and Rochester as well.
There are a lot of variations with signs, and not only regionally! I had 2 deaf sign teachers, at two different levels, teaching from the same vocabulary lists and I learned two totally different sets of signs. A few of them were the same, but many weren't.
My first teacher was oral until age 18, grew up in FLA, and learned ASL at Gally. She moved to CA 35 years ago. My second teacher is 5th generation deaf, (he's actually HOH), grew up in WIS, and he moved here about 15 years ago. They sign SO differently. I went to a free ASL tutor, deaf, after I had taken the class with the second teacher, and she was having some trouble tutoring other students because she couldn't remember which teacher signed which way! I remembered a lot of which signs went with which teacher, and I helped some, but she still got confused sometimes. These were 2 teachers, at the same school, both deaf, and both teaching from the same list. For me, the classes were really helpful, because I learned a lot about the different ways people sign; but for many students, it was very confusing.
I have noticed a lot of variety in the LOAN signs. Some deaf include all the letters, some don't. There are 2 (at least) different ways to loan sign "STYLE," I think this is the perfect example.
Also the ASL sign for "blow up, lose ur temper" has 2 signs (at least). Here, in CA, the sign for "fabric" and "land" is the same- but it isn't everywhere. We also have a lot of signs for mexican food, like tacos, that are not used across the US. The sign for TACO here is the sign for SANDWICH in the midwest. The list could go on and on.
Also though, what we have to remember, is how many synonyms there are for words in English. So many hearing students complain about deaf people's different sign styles, but I think we hearing have just as many different speaking styles. Okay, adios,