The question of how one might set up security on a wireless router has more than just encryption behind it: one can set up a wireless network (configure the wireless router) so that it doesn't show up at all to "strangers passing by". Or it can be set up to show up, but only allow certain specific machines to connect. Or it can be set up to allow anyone to connect who "knows" a certain Key. Or to allow anyone within range to connect.
Wireless routers tend to support "A", "A/B", or "A/B/G" (and "N"), and you'll be looking for your laptop (or Mac) to use "A", "B", or "G" on its wireless interface. Whether that wireless interface is built right into the computer, or is added as a PCMCIA card (or PCI card, for desktop PCs) doesn't matter. Bluetooth is another beast entirely, and isn't generally used for communicating between a laptop and a router.
For example, Apple mentions "n" as well as a/b/g support for the
MacBook, and most newer laptops come with wireless support built in.
