If your laptop supports PCMCIA this is the easiest and fastest way to get network support. Make sure your card is supported before buying one.
Probably the cheapest way to connect your laptop to another computer, but quite slow. You may use PPP or SLIP to start the connection.
Accton Pocket Ethernet and Linux This ethernet adaptor uses a parallel port and delivers approximately 110k Bytes/s throughput for those notebooks that do not have PCMCIA slots.
Linux and Linksys Ethernet Adaptors A short note on the use of the Linksys parallel-port ethernet adaptor under Linux. This is a widely available networking adaptor that doesn't require a PCMCIA slot.
Offers more speed than a serial connection. Some laptops use chipsets that will not work with PLIP. Please see PLIP-HOWTO for details.
I don't have experience with a NIC in a docking station yet.
PowerBooks come with built-in 100Mbps Ethernet, which works fine under Linux.