The HP 720/722c series of printers is one ongoing headache for the linux community. The printers work pretty good, the price was right, and the name brand helped sell alot of them. but they use a proprietary win-printer driver, which HP, despite it's lipservice to Linux support, still holds close. There has been an ongoing effort to reverse engineer the drivers for this printer, and currently I believe it supports 600x600 color. I haven't used e-smith yet, but on a regular RedHat install, w/ printtools and rhs-printfilters installed, just run /usr/sbin/printtool as root from a command line. A gui configuration dialog should pop up, and it makes it about as easy as it gets to set up a Linux printer.
Monte