Firstly Raub, I hope you don't mind me borrowing your bike picture, if you do let me know and I will remove it.
I wanted to see how different a bike with proper trials geometery would be from my XC Scott Aspen which I am struggling along on right now. A Base 26 frame seemed to be a good starting point so I borrowed Raub's picture of his bike from a similar angle and messed about in photoshop to get the overlay.
For a reference point I matched up the rear axles, from there you can see my BB is over an inch lower and the chainstays are two inches longer. At the other end, my bars are an inch behind, yet my front axle is an inch in front of the base axle.
So basically between the bars and the BB i get three inches less working room than I would with the base which -correct me if i am wrong - is considered a short frame. Also the relaxed head angle makes getting the back wheel to come up bloody difficult and the low BB means i smasha lot of chainrings.
Hope some of you found this a useful way to compare geometry,
PS Photoshop/help - layers, transparency.