Microchip recently released the ENC28J60 which is an Ethernet to SPI bridge. I haven't yet seen any sample PBP code to make use of it.

There are numerous manufacturers who supply Ethernet-to-RS232 devices, frequently called serial servers. Some provide virtual serial port drivers for the PC end so legacy software sees them as serial devices. You can handle the PIC end with PBP code. The Lantronix XPort is one such device.