Really, "double posting" (putting the same post on more than one forum here) is a "Bad Thing" (tm). It makes it very hard to keep a conversation's responses all together, and often results in having two different conversations going at once. Please, only post in one forum at at tame for the same issue.
Yes, but I'm not sure what is involved in doing it with iWEB.
Essentially, you set "widths" to be percentages of the screen size rather than in pixels, or other "fixed" measurements.
Note that this is actually related to the resolution of the screen (the number of pixels displayed on the screen), not the physical size of the monitor (though generally speaking, those with smaller screen dimensions usually use lower resolution settings).