Is there a notification or "pop up" notification that an open wifi connection is available? Is it possible to auto-switch to wifi when a strong enough signal is present?

I understand that n900 can be told switch automatically to wifi if it finds one for which it has the connection details (and preseumably an unsecured one).

It won't connect automatically to previously unknown unsecured networks, and that's a good thing since using such networks without the owner's consent is illegal in certain jurisdictions.

Consent is pretty explicit when DHCP offers an address and gateway.

When turning the knob opens the door of a house that does not mean the owner consented to anything - he just might be careless/reckless about security, none of which make you less responsible.

DHCP request equivalent: "Knock, knock, can I come in?"
DHCP offer equivalent: "Of course! Here's a chair for you. Help yourself to the beer."

This AP is saying that its owner consents and welcomes users.

Stop. 99.9% of wi-fi router owners don't know what DHCP is, let alone that their wi-fi router has this feature or how it works.

Don't fire up this discussion again, it's been gone through lots of times on this forum over the last years and there's no need to revisit it. You just joined so you wouldn't know that.

Good luck convincing the FBI etc of that

Idiocracy reigns.

Actually, a notification is probably better. Just a pop letting you know that there is an available decent wifi connection. So that I can switch and not use up 3g data when I don't have to.