Hi, unhappy
This site has some good information and tools for measuring your upload and download speeds :)
Browse around, there is other useful stuff on the site as well
http://www.pcpitstop.com/internet/Bandwidth.asp
EDIT: Further thoughts.................whilst you are downloading there must be a fair bit of handshaking going on? which means that you are uploading as well. So if the computer sending the packets is not getting acknowledgements fast enough, it will presumably slow down to a rate where it is?
Also, your 56.6 modem is asynchronous, in that it will only upload to a maximum of 33.6. I seem to recall that the theoretical maximum upload/download for a 56.6 modem is around 64kbps, so maybe there is some sort of load balancing going on within your modem?
IIRC 28.8 modems did not display this? and were certainly synchronous, and had a total capacity of less than 64kbps. Also I am using dial-up ADSL now, and find that the downloads tend to accellerate to begin with then settle down, rather than the peak and rapid decline when the download starts.
