wireless networks

ok so i just got this cool dell laptop, all decked out and it came with this wireless network card. I bought a wireless access point. Any of you have experience with wireless networks?

Im trying to figure out if its worth the effort to WEP the network, and if i really should be that worried about someone within 300feet of my house surfin the web on my connection.

How big of a deal is this?

on a side note: being able to sit in my backyard, with a beer, a buger, tunes and the setting sun is pretty cool.