I feel your pain, RC. My only options are dial-up, or ISDN for more cost than a broadband connection. I have the ISDN.
There is a firefox extension that works VERY well. And its not just for youtube. It will download basically anything with media that you choose for it to download, and its conveniently located on your menu bar.
http://www.downloadhelper.net/ The format converter part of it requires a bit more knowledge of formats and additional software, but if you do desire conversion of your videos, it is capable. For simplicity, just click "install the extension".
You will also need a .FLV player for youtube videos, if you don't convert them to another format.
http://www.martijndevisser.com/blog/flv-player/ It's small in size (5MB), and its free. It does have a bug or two, like window resizing issues, but its FREE!