You can play across 2 monitors without DH2go, but like I said its pretty pointless unless the game supports it properly.
I have a 19" widescreen and a old CRT for the games that dont like widescreen. (EA!!! :roll: ) So I can span across these at 2048x768 and games run fine at this resolution if they support it that is, but as I said they are really unplayable. Even if they were exact monitors it would still be pretty useless.
F.E.A.R:
Guild Wars:
This is really badly vert- its not funny.
Now image a big fat gap/bar straight down the middle of those pictures.
Also when using dual monitors your games will slow down quite a bit, so thats also a draw back.
So just use the drivers to switch between Horizontal Span and Single Display before you game and it will be fine. :)