The "padlocked" wireless spots are secured networks that local residents/businesses have. You cannot access them without the password that those residents/businesses set up for their system. You have to log into your own wireless network via a router or go to a Nintendo wifi hotspot. You can find out where the hotspots are near you at nintendowifi.com
In Pokemon What is a wireless aptapter
you go to the wireless club in any Pokemon center( make sure you have a wireless adapter)
Yes You Can.
== ==
Pokemon emerald or through global wireless trade
U can trade with the help of a wireless adapter.
get wfi
No.
You get someones friend code -Pokemon Master
Yes, or a wireless transmitter.
on the top of wireless tower
yes, emerald is combatible with the wireless adapter... but it is not compatible with the built in wireless in the Nintendo DS