As a number have mentioned, you can bring a wireless router. If you have one at home (and you do if you have wireless access in your home), and you have all your computers and Itouches in the home, including theirs, already able to use it, you can bring that router, its electrical hook-up, and ethernet cord (or just use one in room), and just connect it to the ethernet socket in the room and a electric socket and wella you will have wireless access (if you are using a password with the router -- you should be -- you just need to make sure their new computers and the itouch have already logged into your router at home with that password and saved it and also make sure you know what the password is just in case you need it when there).
So I just want to interject a quick comment. If your home router (sometimes also called Customer Premise Equipment, CPE) is provided by your ISP, it may or may not work. As configured for your home service.
Reasons for me saying this are FIOS comes with a router, but it basically has an integrated cable modem in it. It's set up to so the "cable connection is the upstream connection." You can mess with the configuration, and get it to route via the ethernet, but by default it doesn't do that.
Some home services, almost all DSL services and some cable services, use an additional protocol called Point-to-Point over Ethernet, PPPoE. If your router/modem is setup to do this you'll need to change the settings so it just routes/NATs without the PPPoE. If your service is via PPPoE your account and password will be saved in the router.
I would not advise people to do this, in general. If they do this you should backup your home configuration before you take it with you. So they can get it back to where it was working when they left.
Personally, I don't don't take my home equipment on the road for 3 reasons. 1) it works where it is, and a second pocket router to carry with me was only $80. 2) I have gear at home, like my Tivo (so it will continue to get updates), and my Network Attached Storage, NAS (so I can backup my photos to my home) which I like to keep running when I leave. 3) I'm paranoid about getting my gear stolen/broken durning travel.
Finally you can duplicate your home wireless setup with your travel unit. (which is what I do.) The computers don't care, unless you are using thing more for home wireless security than just WEP/WPA2 Personal.
johno