Owning a wifi-only Ipad means that it's a constant adventure for me to explore new ways of going online when I'm not at home. One method that I've been successful with is to install and use this nifty free beta software from Connectify (www.connectify.me) .
Basically, what it does is to convert your wi-fi capable desktop/laptop into a wireless access point. So if you happen to be on a business trip in a hotel that only has an ethernet access point in your room, you can tap that internet connection for your Ipad (or even your Iphone in order to save on expensive 3G data roaming charges). The catch is that the software only works with the Windows 7 OS and I suspect hardware compatibility will have to be checked out (but hey, it's free!)
I had to jump through some hoops to get Connectify to work on my corporate laptop because I didn't have full administrator rights but there were workarounds (in my case, installing the software with help from the IT department).
The second method which I haven't tried, but many folks have had success with, is to use the Huawei E5830 mi-fi router. This Huawei mi-fi router works like a mobile wi-fi access point and since it runs on its own rechargeable battery, allows for true portability. It is small enough to sit in your shirt pocket and allow several wi-fi devices to share one mobile broadband connection. It's something that I've been meaning to purchase but I'm still waiting for prices to drop further. It's currently priced at about S$160 (~US$130) and it would be fantastic for me since I have an unlimited free data plan for my mobile broadband usb stick that should be usable if I transfer the simcard to the mi-fi router.
The lengths people will go for free wifi access...(Oh why didn't I get a 3G Ipad???)
The Huawei E5830 mifi.