56k dial-up modem with squirrel powered copper lines - I connect at 26.4k on a GOOD day - most days are 19k-21k. Good thing I have a T1 at work - 2.6MB/sec
It is getting more common but there are still a LOT of people on dialup and you always need to keep that in mind when building websites or you will alienate a lot of users.
Using a BellSouth DSL "Extra," I think it's call, I'm averaging 2200Kb in average throughput. Can go as high at 3000Kb if no one else in the world is online.
I only stepped up from dialup a few weeks ago. On the dial connection, I hated and avoided sites that start up with multimedia or lots of graphics. I think a good site should start simple and give people options to select before any heavy bandwidth.
Definately, if you want a large site with lots of flash and content you should also make a more basic page and give the user the option to pick what page they want to see based on their connection speed.
Sure, I will take care of slow pokes because I was one myself until recently. I just want to get a handle on how many have broadband. Large is kind of a relative term. I was taking a look at my old web site which was never more than a quick and dirty place to dump the tutorials without regard to how it looked or what order it was in and I was shocked that I snunk in some thumbnails that weighted at at 200K each. Oops, I forgot to deselect save profiiles and layers when I made them in Photoshop. Nobody ever complained.