Assuming your wireless LAN is wlan0 you can add this to your /etc/network/interfaces file. It's probably not a good idea to use this since it's setup to use WEP, but I'll let you figure out WPA2.
auto wlan0 iface wlan0 inet static address 172.16.0.1 netmask 255.255.255.0 broadcast 172.16.0.255 post-up iwconfig wlan0 mode Ad-Hoc rate auto essid "raspberries" channel 1 key 1234567890
You can setup a DHCP server on the RaspberryPi or you can configure a static IP such as 172.16.0.2 on your machine and SSH into the RaspberryPi through 172.16.0.1.