If I keep my main broadband coming in on the ethernet LAN socket, but also have another (separate) ADSL feed on wi-fi coming in on a USB wireless stick will Windows SHARE the broadband from both sources or just give one priority?

Thought it would be a simple way to double broadband speed as I will be borrowing the wireless network from my neighbours by arrangement while they are away......just wondered if it would in fact increase my available speed or would make no difference....is Win Xp intelligent enough to work out it has 2 broadband signals coming in on different sources?

Doubt you will get the speed boost you hope for.
I can't see windows having any sort of widget (eg. loadbalancer) for 2 networks.

I guess it may be possible to setup so all of a certain kind of content goes through one network and everything else through the other (eg. xbox thru one and http through the other).

I'm dimly aware that you can do this with linux and some sort of funky gigabit ethernet, but then linux can do most things.

I think at the very best that you could only configure differernt programs to use the different connections by referencing their IP addresses, but for simply doubling the speed of your t'internet.... I don't think so.