So today, I finally decided I should try to make it as simple as a keystroke. First, I created an AppleScript (my very first, no less):
tell application "Finder"
eject "name_of_my_iPod"
end tell
I saved it as an application (but I guess you can save it as a script) in ~/Documents -> scripts. Then, I went and downloaded Xkeys. After that, I installed Xkeys, assigned F13 to run the script application, and voila! F13 is now my own "eject iPod" key. I just wished I could assign F16 for the task, as the keyboard that came with my iMac G5 has F16.

