At times I'm running an open wifi hotspot. So far I've decided to go for an unencrypted wifi channel. I don't mind if you use it to check your mail, read some webpages or be productive in a low bandwidth manner. Of course I kindly request you not to use bittorrent or other bandwidth hogs such as high quality video.
I can do this because I'm using Mobile Vikings, a great little company based in Hasselt with a mission: mobile internet for everyone (at least that what it seems like with these prices).
It's all pre-paid and for 15 euro you get... 15 euro of calling credits, 1000 SMS messages (during one month) and 2 GB of data. Apart from that you can also use your credit abroad, in Western Europe and the United States you only pay 50 cent per megabyte when you're roaming. One reason to live in Belgium ;)
If you consider signing up, please do through my referral link so I get one top-up free... It will also encourage me to leave my wireless hotspot unencrypted ;)