After many hours, phone calls, and profanities, I am printing wirelessly using a Linksys WPS54G Print Server. I am printing from a Powerbook G4 running Mac OSX 10.4.5 to an Epson Stylus Photo R320. Here's what worked for me:
Ensure your existing wireless network is operational, i.e. router connected/functional, and computer AirPort card turned on. Plug the Print Server power adapter into the wall outlet. Attach power input to Print Server and wait for power led to glow. Attach printer USB cable to printer input and opposing cable end to Print Server USB port. Wait for USB led and Wireless led to glow.
On your computer, open your Web browser and log into your Print Server. For this application (WPS54G), in the address bar type 192.168.0.11. A login window will appear. Leave "Log In Name" blank and in the password field, type the word admin
Once inside the Print Server, you may see your Print Server's name. It probably corresponds with the Print Server model number, in this case WPS54G (write down the name of your print server).
From the Print Server on screen menu, select Protocol from the menu.
Inside Protocol, click "Use the following IP Address." To keep things simple, in the IP Address field enter an IP whose first seven digits match your computer's IP, ex 192.168.0.XX. Change the last to numbers to anything you like other than what your computer is using, ex, .78. (write down the Printer Server IP Address). In the Subnet Mask field, enter 255.255.255.0. In the Gateway field, enter your router's IP (this can be found by opening System Prefs, choosing Network. In the "Show" drop down menu select AirPort. With the AirPort window open, click TCP/IP, and you'll see your IP addresses).
Once your Print Server IP, Subnet and Gateway info are input, click Save.
Back to your Print Server web browser, select "Wireless" from the on-screen menu. Click the Basic tab, and you'll see the SSID field. Enter the name of your wireless network in the SSID field. You can see the name of your network by clicking the AirPort tab in you computer's menu bar. Type the name exactly and click Save. Now you can exit the Print Server browser.
On your Mac, open System Preferences and select Print & Fax. Click on the "+" icon (lower left) to add a printer. Click on the IP Printer icon (top). Select "Line Printer Daemon – LPD" and do the following:
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060404021600193