Sorry, couldn't resist that. I use "save for web" to size a pic in Elements II which is what I've been using for years...'cuz it's too hard to change...and within certain parameters it allows a bigger pic for a given res. Most of the pics I post are set to 1200 by 900 and then sized in the "save for web" on the sliding scale thingy.

It doesn't always work, I guess it partly depends on the density of the pic. I tried it with a pic of a turtle on the sand and it wouldn't get under 100k at 1200 by 900 but here it is in 800 by 600.

If the pic is "difficult" you lose some precision in the clarity as you slide down the line but in general I figure it's close enough for jazz....