Normally you can do this:
<select size="3">
<option>blah</option>
<option>blah</option>
<option>blah</option>
</select>
And it would render as a selectionbox where all three options are visible (without dropping down)
I'm looking for a way to set this size attribute from css.
I disagree, I have been able to set select width and height using CSS with something like this:
Works in IE(7) as well as I just tested it.