I don't think that's a very good idea. Basically you're hijacking someone else's web service and bandwidth. That's like tapping your neighbor's outdoor electric outlet. Not very legal or ethical and brings up privacy issues to boot.

I agree, that is why I was asking- The bandwidth issue is obvious...

I noticed that when I turned my computer on it found 'Open' networks that did not require any password to use, this surprised me and I wondered about it...

The question is moot now since I went on to install my own router, but I am concerned that my wireless is open to everyone...

I do know some people intentionally allow their wireless network to be used by other people- I wouldnt really mind if an occasional person used mine to browse or send email, but I an concerned about abuse....