http://en.wikipedia.org/wiki/Isomorphic_keyboard
These tackle the problem of how the normal piano layout requires different motor-memories for the same interval-patterns at different pitches .
Janko and Wicki-Hayden are examples , as is layout of the chromatic button accordion .
http://en.wikipedia.org/wiki/Generalized_keyboard
These are designed to work for various other tunings than standard 12-tone tuning ; i think most of them map some pitch-space to a hexagonal grid .
I got my diagnosis 3 years ago , after a melatonin-test . I had to do 24 saliva samples at 24 consecutive hours , they tell you from the graph whether your melatonin production is off .
The 'fix' is to take melatonin , as a pill , same time every night .
For some that's close to a cure , for others it isn't (it drags my sleep phase about 50% towards a normal phase , if i take it further than that the fatigue kicks in again ) .
Once you get diagnosed a doctor would start you off at 5mg , you can lower the dose later on .
So go get diagnosed , unless you think you can diagnose yourself .
Most of the advice in this thread is about sleep hygiene . That's important but it wont rid you of DSPS if you have it .
Then there's some comments about playing with 'zeitgebers' , by fasting , or light-therapy , or dark-therapy (F.lux, you can even wear blue-blocking sunglasses) . These will help you influence your sleep phase .
But the thing is : all of this doesn't do enough for the more serious cases . Those just need melatonin .
And yes if you tend to go into a 27-hour cycle in the summer , you're considered a serious case .
(It something like brainstorming with your eyes closed and describing all of it into a tape-recorder . Feels really akward .)
http://www.winwenger.com/imstream.htm