I have an OKI C5300 printer that has ethernet and supports network printing. I currently use it in NetBIOS and LPR mode, but now I've found a much stranger way to print.
I find that I can FTP to the printer, logging in as anonymous, transfer a postscript file to the lp directory, and the file will be printed. I have a copy of NetDrive, so I defined a drive letter, P:, to be the printer's lp directory. Now I can print using any postscript printer object, save to a file on the P: drive, and the file will print.