Not sure if this is what you mean, but the firebug add-on for firefox has a "Net" panel that can show you request times.
Regarding testing with different bandwidths, that's a really tricky problem, since in the real world, there are also things such as packet-loss and different round-trip times etc. to take into account. I can't recommend any specific tool, but I think it's worth pointing out that bandwidth is not the only consideration...
WebSiteOptimization.com has a tool which will allow you to enter a URL and it will report on estimated download times for the HTML and all of the related images and other assets. They will also make recommendations on how you can improve your load times.
Not sure if this is what you mean, but the firebug add-on for firefox has a "Net" panel that can show you request times.
Regarding testing with different bandwidths, that's a really tricky problem, since in the real world, there are also things such as packet-loss and different round-trip times etc. to take into account. I can't recommend any specific tool, but I think it's worth pointing out that bandwidth is not the only consideration...
You may use echoping a nice program to test performances of a remote host.
WebSiteOptimization.com has a tool which will allow you to enter a URL and it will report on estimated download times for the HTML and all of the related images and other assets. They will also make recommendations on how you can improve your load times.
If you're interested in improving the speed of your web site in general, I recommend two books by Steve Souders, High Performance Web Sites, and Even Faster Web Sites.