Here is how to turn Raspberry PI with Linksys WUSB100 v2.0 adapter and Raspbian into wireless access point. This might be handy for conference rooms where you have wired connection, but wireless signal is too low. Just quick setup on Raspberry, plugin the cable and you have wireless available.
Install required packages
apt-get install firmware-ralink wireless-tools hostapd bridge-utils
Modify /etc/network/interfaces to add bridge interface
auto lo br0 iface lo inet loopback iface eth0 inet manual allow-hotplug wlan0 iface wlan0 inet manual iface br0 inet dhcp bridge_ports eth0 wlan0
Once network configuration is modified reboot Raspberry PI.
Create /etc/hostapd/hostapd.conf file to define access point configuration
interface=wlan0 driver=nl80211 bridge=br0 country_code=PL ieee80211d=1 ssid=raspb3rry-wifi hw_mode=g channel=6 wme_enabled=0 macaddr_acl=0 auth_algs=1 wpa=2 wpa_passphrase=raspberry123 wpa_key_mgmt=WPA-PSK wpa_pairwise=TKIP rsn_pairwise=CCMP
Add configuration information to /etc/default/hostapd
That will make hostapd daemon to start automatically each time Raspberry PI will bootup.
DAEMON_CONF="/etc/hostapd/hostapd.conf"