i'm afraid i can't help to much with bluetooth.. except i can tell you that it isn't near as popular as standard wireless tcp/ip routers. basically all routers/switches/hubs have the option to plug multiple computers in. thats what they're designed to do.

sorry i couldn't help anymore than that.. i know more about windows and hardware inside a pc than networking and etc..

Chances are good your laptop came with at least one (or more) wireless features built in, to include an 802.11a or a/b or g adapter. If you only want to wireless communicate with one other computer, and that computer has an open PCI slot, get yourself a wireless PCI adapter. This will cost you anywhere from about $50 to $150 depending on brand chosen. These two computers can be set up in what's called "Ad-hoc" mode, meaning, they will be wirelessly communicating without an Access Point. The other option you mentioned - sounds like either a combo Wireless/Switch/Router, is also known as an Access Point. There are many of these on the market for around $100 that do up to three things for you: allow you to share an Internet connection (like DSL or Cable) with up to 4 or 5 hardwired Ethernet PCs. The Internet sharing is the Router function, the 4 or 5 hardwired Ethernet connections is the Switch function; and you can also have a whole bunch more computers wirelessly get to the Router to also share the Internet - this is the wireless AP function. Some of these also have a built-in Print Server and may support some advanced internet features like firewall protection and VPN connectivity.

Blue-tooth, the last I looked, was for very short-range (like, within your living room) wireless connection of peripherals to a computer. For instance, your free laptop, if it has bluetooth built in, could be the master computer so to speak that all your bluetooth peripherals - printers, cameras, PDAs, etc, could communicate to/through.

I am assuming that you already have a hi-speed internet connection.
If so, find out if there is a Frye Electronics store in your local area. You can buy a wireless router there for $21.99. If not go to their website at http://www.outpost.com. It is an Airlink AR315W 54Mbps Wireless-G Cable/DSL Broadband Router (Item #: 4056592). I have one and it works great.