Digilent, a partner of Xilinx, makes eval boards for Xilinx FPGAs. I bought one and plan to hack some Verilog with it. My past experiments involved a board of my own design with a FPGA and a USB-enabled microcontroller. I successfully programmed the microcontroller over the USB cable to wiggle GPIO pins, which should have allowed me to program the FPGA via JTAG. But for some reason, JTAG programming of the FPGA didn't work. This time the JTAG programming pins will be wired directly to parallel port pins and there is a Linux library for programming them, so I should have better luck this time. Fewer unknowns and variables, more easily probed.
Attention (hey, shiny!) deficit break: I stumbled across a couple of very affordable logic analyzers. Amazing stuff, just the thing for debugging errant JTAG signals.
Some nice folks have released a PCI soft core under the LGPL. I'm not ready to tackle that yet, but hope to get there before too long. Speaking of PCI,
here is a nice FPGA board for a PCI bus slot from Enterpoint in the UK. They also have a PCI soft core but the licensing is a bit pricey for a hobbyist. I wonder if the LGPLed PCI core would work on the Enterpoint board.