What type of connection speed do you get when you dial in? If it is lower than 48000, there may be some electrical interference in your phone lines. Try turning off different appliances to see if that changes anything.
You can use the compression / proxy servers that are offered by many ISP's. They compress images and do some other things so that web contect gets to you a little faster.
If you are reading websites with lots of graphics, you can turn off images in Internet Explorer or Firefox. Pages will load lots faster, and you can view any image that has been blocked by right-clicking on it.