I used ftp commander for a while. Not a bad freeware solution, very basic, but gets the job done. Now I've switched to cute-ftp but I realize you want to avoid commercial solutions.
I like CoffeeCup Free FTP. It does everything that I need and its free. http://www.coffeecup.com/free-ftp
when I'm away from my home pc, i use fireftp with firefox. When i'm on my laptop i use file-surfer and when i'm at my desktop i use filezilla. i have to say though, that filezilla is best (user-friendly, fast etc.)