Charles-Axel Dein's blog.

Mounting an S3 bucket on Mac Os X Snow Leopard

Warning: s3fs I/O is broken on Snow Leopard (10.6). Here are the steps if you want to check it rapidly though:

Prerequisite: brew, Mac Os 10.6

$ brew install s3fs
$ sudo cp -rfX /usr/local/Cellar/fuse4x-kext/0.8.12\
> /Library/Extensions/fuse4x.kext /System/Library/Extensions
$ sudo chmod +s /System/Library/Extensions/fuse4x.kext\
> /Support/load_fuse4x
$ chmod 600 ~/.passwd-s3fs
$ mkdir /Volumes/s3
$ /usr/local/bin/s3fs BUCKETNAME \
> /Volumes/s3 -olocal,ping_diskarb,volname=S3
$ open /Volumes/s3

For more information please check AmazonOverFuse.