Just a quick one…I wanted to be able to find out, quickly, the weight (ie. the total size of all files) for any given page on a site. Page Info will give you some help, but it doesn’t always seem to work and it doesn’t give you a total.
Anyway I hit Google and stumbled upon this simple and not very well publicised Firefox extension: Fatweb, by Paul English. Promised developments don’t seem to have materialised but even in its basic form it’s useful — it gives a running total of bytes loaded, in the status bar. On click you get a list of all files and their sizes, with estimated total download time.