[wplug] wi-fi security?

[Zachary Uram]

Got a new laptop and was wondering about wifi security. I've never
used wifi before. I wanted to go to some of the local coffee shops
that offer free wii but I need to know:

1) How do I setup wifi in Linux?
1) How do I detect and connect to public free network(s)?
2) How do I make my laptop more secure so others on wifi network can't
steal or sniff my packets?

I heard many people using free wifi get heir passwords sniffed, etc.

Running Ubuntu 9.04 and Debian 5.01 triple boot with Vista Home Premium.

Any Linux programs for detecting available wifi signals and connecting
to them and any wifi security apps?

Also another problem is that when at home I want my laptop to be able
to share my DSL connection, right now my desktop is connected directly
(static IP, no PPoE just raw ethernet frames) to the DSL modem and I
was hoping I can keep this setup and find a way to attack my laptop
when I want to use it at home so what hardware would I need and how
should I set it up?

So right now I have:
phone jack ----> UPS ----> DSL modem ----> desktop NIC

I setup the networking manually by editing the appropriate files. I
want the laptop to automatically connect to the wired network at home
when I connect it and to wireless networks also, not sure if this can
be done.

Zach