You need to consider what people are viewing at, very few people use 800X600 anymore. You may have been the last one... LOL

Sites I'm doing now will safely display within a 1024 wide resolution which if I remember correctly it is the most popular at the moment but I think that will be short lived with all the wide screen monitors coming on the market.

Well aware of 1024... used that a few years myself and--at the time, saw no need/reason to deal with the 800 width pages (all are centered and thus worked okay). TODAY however with so many monitors 1200+ and pages (liquid or otherwise) formatted to fill the screen, these pages which have been up since 1996 appear to need an overhaul.

Even with broadband more common, at what point does a 100 image thumbnail page not work?

And how many older folks ZOOM or use LARGE FONTS etc.? Me being one of the older folks.

Do we code for kids with sharp eyesight? Can we depend on the mom and pop (that's most of us) being smart enough to figure out how to use screen zoom if they are not using FF?

In a wide screen world, which is becoming more prevalent, what size
THUMBNAIL makes sense without slowing page, etc.

When I started webmastering 640 was the norm. And take it back a year or so earlier and all my graphics from 1983 to 1994 were ansi (BBS). :)

I think 100 is too small under any conditions for a thumbnail. 150 would probably be the smallest I would use unless the space didn't allow it such is in side navigation panel. Unfortunate but you have to design for the masses and the masses use 1024. You can't cater to everyone, my take on it is that those using other resolutions will adapt.

BTW the zoom feature is already implemented in IE7.

What matters here is what size screens and browser windows YOUR visitors use. Who cares what the masses use?

And don't forget that large monitors don't mean folks are viewing your site full screen.

If I visited your site you might look in your stats and see that someone had a 1600x1200 monitor. But would you know that my browser window was only 800x600?

Why would I care what window size is used? RESOLUTION. My once nice thumbnails now look like smudge spots. :)

I'll resize up since these are art prints we'd like to sell. Those who use less than full screen can adapt... by scrolling to the right.