what screen size is best for daytrading?

No, never.

 

What do you mean exactly? Wide screen types?

 

yes... wide, like a cinema screen.

In that case, you can use 2 LCD instead of 3? would it work?

 

I have three 19" LCDs and one of them is a wide screen, I placed the wide screen in the middle and the regular on each side,
Works fine.

 

Not necessarily, and there are advantages to VGA... some settings are not available on DVI.

Many who have DVI and VGA running side by side claim to see "no difference". Some say you'll only see the difference at 1600x1200 or higher.

Having a quality video card is essential, especially for VGA.

 

And what would you do with four feet by four feet screen if
projector has 800x600 resolution(maybe 1024*768)?

 

Usually the best resolution is the native. In this case, 800x600 and sit way back from the screen.

 

I think one should rather get stronger glasses before going down to 800*600...
Personally I run 4*19" w 1600*1200 plus 2*21" w 1600*1200, I have som space between me and them, and it works FINE.

 

I guess I would have a problem.

 

Gnome,

Thanks for wording your post the way you did. I have two 17.4" monitors and was looking to buy three 19 inchers to add to my setup. I didn't realize that I would be seeing the exact same screen since the resolution on both sizes are the same. Therefore, I think I'll buy some 17" monitors or wait for a deal on the Dell 2005FPW.

And I thought I was computer savvy!