I'll agree with Daniel that sometimes, it's useful to have vertical table separators.  Here's how I kind-of do it:

| asdlfj |   | alsjfdas |
|--------+---+----------|
| alsdjf |   | aqsljf   |
| asdljf |   | asldjf   |


This is visible enough inside of org-mode and it yields a widish gap in exported html -- a horizontal screen space waster, though.  I suppose one way to denote a vertical separator without adding an extra symbol would be to allow tables in org-mode that look like this:

| asdlfj || alsjfdas |
|--------++----------|
| alsdjf || aqsljf   |
| asdljf || asldjf   |


Scott
Date: Fri, 13 Apr 2007 06:23:16 +0200
From: Carsten Dominik <dominik@science.uva.nl>

On Apr 12, 2007, at 20:48, Daniel J. Sinder wrote:
  
>
> I think rejecting vertical rules as a matter of style is a mistake.
>  Whether you consider org-mode tables to be a markup or a
> spreadsheet, it's peers -- HTML, LaTeX, Gnumeric, Excel, etc. --
> will all produce tables with vertical rules if asked to do so.  I'm
> wary of tools that enforce style.  I'd prefer to read the style
> guide and then decide for myself (that is, use it as a *guide* not
> an edict).
    

Fair enough.
  
> However, if vertical rules are too clunky, difficult,
> time-consuming, or low priority to implement, that's an entirely
> different matter that I can fully understand.
    

As I said, I don't want to have a special separator for this,
implementation would be very cumbersome and I'd like
to be able to have ! as a character in a table field.
Maybe something like a special #+FORMAT line above the table
to set special formatting directives.

- Carsten