Great tutorial here:

http://www.ifelix.co.uk/tech/3020.html

Do you have a computer on your home network that has a lot of music that you wish you had access to from your other computers? Well, you can have access with just a few clicks.

Make sure that you have your computers set to share files on your network. Then, all you have to do is on the computer that has all of the music, do the following:

01. Open iTunes on the machine that has the music you want to share
02. Go to EDIT>PREFERENCES (PC) or iTUNES>PREFERENCES (Mac)
03. Click on the SHARING tab
04. Check the box next to SHARE MY LIBRARY ON MY LOCAL NETWORK
05. You can opt to share your entire libary or just certain playlists
06. You can even require a password if you want by clicking the box next to REQUIRE PASSWORD and entering the password
07. Click OK
08. On the computers that you want to access this library, go into PREFERENCES above via Step 2, and check the box next to LOOK FOR SHARED LIBRARIES
09. Click OK

*iTunes must be open on the machine that has the music library that you are sharing in order for the other machines to be able to view and access it.
10. Done!

Go here:

http://www.ifelix.co.uk/tech/3015.html

I just found out about www.boingo.com. They offer a free wireless configuration utility that works with most cards, and that supports WPA encryption. The link is at the bottom of the page. It’s great for older laptops.