SuzyUK - 3:45 pm on Oct 22, 2010 (gmt 0)

Is there a way I can get rid of that 3 pixel right side margin on my columns? margin: 0px doesn't seem to have any effect on it.

Yep.. set it to be margin-right: -3px; and change the IE one to 0 (zero)

Seems like I'm getting a little bit of odd top spacing too. Any thoughts on all the spacing?

possibly the different table padding rendering? - though most likely the real inline-blocks also have top/bottom leading, they basically act like a word or an inline image, any inline element allows 3-4px top and bottom spacing which would be the normal spacing for ascenders and descenders of letters like b, y etc.. i.e. the "line-height" bit - it could be that?

AAAAAAND one more question. Is there a way to auto-balance the columns? That is, have the column set fill the whole width, but have each column width auto size based on content? The same way a table would, if you specified the table width as 100%, but no cell widths?

No I don't think so, percentages is about the best you could get..

I don't think the CSS Column module which would solve all the above and more is ready for widespread use yet.., so (and pssst.. don't say I said but) why not just use the table it's probably less markup ;)