Yes, it's not easy, but Al has been hinting that if people want larger images he may be able to support them. I've given him a few ideas of how this could be done without inconveniencing those with low-resolution screens and without requiring lots more disk space and bandwidth. My article on panoramas is with him now: I'm waiting for the first suggestions for revision. I think you would enjoy having a "real" panorama camera. Even the inexpensive Russian Horizon would be fun. But you'd have to mess with film, again!
For stitching, use files as big and with as high definition as you can cope with in PS, and only reduce the final image. This way there is much less degradation along the way. If you have a PC-Windows setup, I know stitching programs that can make life a lot easier, too. PS is a really blunt instrument for stitching panoramas, and you are doing remarkably well! I take my hat off to you. (By the way, this is a very nice panorama given that the original was probably a LOT sharper...)
Really nice perspective on this cityscape, Dan. I like the vantage point, looking down and with the river and bridge peeking through. Nice use of PS to create the panorama. well done.