I acquired 2 TP-Link WR-700N devices, one to use as a repeater to overcome a dead zone in my house, and one to use as a bridge to connect some ethernet only devices in a part of the house without cables.
The adventure starts when they arrive from China via Ebay: instructions exist only in Chinese.
Never mind, Google Translate to the rescue. BTW, Here's the product page.
Then they are set to be Access Point (AP) mode with no WEP/WPA key (ie open) on the fixed IP address 192.168.1.253.
The easiest way to start is to add a second IP to your computer. On OSX you do this by going to the Network Settings and on the active network add a second:
At the bottom of the window click the "+" sign
Select interface "Airport" if you use WIFI. The name is immaterial. Then click "Advanced"
and then "TCP/IP", change Configure IPv4 to "manually" and put in an address such as "192.168.1.250"
Click "OK" and then "Apply".
Next go to your browser, and open 2 tabs:
192.168.1.253 : The default credentials are admin/admin.
Once you get the hang of having the Google Translate open in the tab next to the web UI to configure the WR700N, it'll be fairly straight forward.
To make your life easier, here's the device's home page, with English translations.
The best place to start is the "Wizard" and work your way through. Flick between tabs to get the translation.
After its configured, you can move to Network to change its IP, and then to System Tools > Change Password. When changing the password I found I had to also put in the admin name "admin".