Steve,

here's a tool that's mighty useful for what you're after called * WebSpeed Simulator * for Windows® 95/98/NT/Me/2000/XP

http://xat.com/wo/index.html

Features:

See how your web site will look on slow links
Make sure text and graphics are loading as you expect
Highlight HTML and Java coding errors
Quality check the designs of your authoring company
Simulate speeds from 1200 bps crawl to LAN speed
View statistics and download times
Identify areas of your site that could be speeded up
Works with dynamic HTML and ASP sites
Safe to try: does not interfere with you machine setup or network

I'm not an affiliate.

Hope this helps.

Rick