Assumes you have a PS2 memory card and a way to transfer files from PC to memory card (e.g., USB adapter, Free McBoot, uLaunchELF, or using a modchip-enabled setup).
A PS2 console, a standard 8MB MagicGate memory card, a PS2-compatible USB flash drive (FAT32 format), and the uLaunchELF homebrew app (requires a softmodded PS2 or a Free McBoot memory card).
If you want, I can: