What model of Amiga is it? If it's one of the later ones (1200, 4000, I think also 600) it has the facility to read/write pc floppies (albeit 720k-formatted ones) built into workbench. Even it's an old a500 you could probably get the software for to do so. The reason PCs can't read/write amiga floppies is that the amiga used more advanced floppy hardware.
Failing that, you can get software for serial/serial or parallel/ parallel transfer. It's slow but reliable, I used to do it all the time. The cables are really cheap (especially if you make them yourself).
You could also get your amiga onto a standard ethernet network if you happen to have the right hardware.
Check out aminet:
http://ftp.uni-paderborn.de/aminet/change.html - you'll find about a zillion freeware ami<->PC solutions.
*dogscoff gronks nostalgically