the K/W thing is mainly broadcast (AM,FM,TV) Hams get anything from a W,K,N,AA-AL all new tech/gens get a Kx# call no matter if they are east/west
I stand (sit) corrected. It is the number than denotes region for Hams not the letter. This explains it pretty well; http://wireless.fcc.gov/services/index.htm?id=amateur&job=call_signs_1
And this from wikipedia; https://en.wikipedia.org/wiki/Amateur_radio_call_signs
And in Australia we have quite strict callsign areas, based on state, as per below with state capital cities in brackets.
VK0 - Australian Territories in/around Antarctica (including Macquarie Island and Heard Island, etc)
VK1 - Australian Capital Territory (Canberra)
VK2 - New South Wales (Sydney)
VK3 - Victoria (Melbourne)
VK4 - Queensland (Brisbane)
VK5 - South Australia (Adelaide)
VK6 - Western Australia (Perth)
VK7 - Tasmania (Hobart)
VK8 - Northern Territory (Darwin)
VK9 - Island/External territories not in Antarctica (Such as Norfolk Island, Christmas Island, etc)
If you're licenced as a VK2, but move to Victoria, and then apply for a new callsign, you'll be given a VK3 call. There's nothing stopping amateurs from licensing themselves in any state they wish, however... But it's $52 a year per license. While legally, i don't think you need to change your call from a VK2 to a Vk3 in the above scenario, it's generally expected that you would get a VK3 callsign if you're going to permanently operate out of VK3.
Makes chasing a 'worked all states' award a lot easier, when you just need to know what their callsign is to know where they are based. And obviously, if you ever hear a VK0 or VK9 on air, jump on it. Rarity after that would probably be VK8 followed by VK7. For special events, Australian amateurs can also use the AX prefix as well, but all other parts of the callsign remain the same - So on Australia day someone could be using AX1WIA, but in reality, it's the same station as VK1WIA, just operating with a special event callsign. The scouts movement also have reserved callsigns available to them with the suffix of SAA-SDZ.
Every now and then you'll find a VI (Victor India) prefix on air too - they're used for special events related to that particular state. I remember using the callsign VI3SAV for a Scouts and Venturers event in Victoria, probably about 18 years ago.
As far as i know, there are no 2x1 callsigns for Amateurs in VK. Pretty sure the 2x1 format is used for scientific licences, eg
VK6C.