Amazon S3 with Ruby aws-s3 gem

I stated using Amazon S3 to store and backup the music I've written and recorded. I'm using the Ruby aws-s3 gem. Note that I check for some basic audio file types so I don't have to manually type the bucket or mime-type.

aws-s3.rb
---------
#!/usr/bin/env ruby
require 'rubygems'
require 'aws/s3'

# File to upload
local_file = ARGV[0]

# bucket & mime-type
if local_file =~ /mp3$/
  bucket = 'doug_mp3'
  mime_type = 'audio/mpeg'
elsif local_file =~ /wav$/
  bucket = 'doug_wav'
  mime_type = 'audio/x-wav'
elsif local_file =~ /aif[c|f]?$/
  bucket = 'doug_aiff'
  mime_type = 'audio/x-aiff'
else
  bucket = ARGV[1]
  mime_type = ARGV[2] || "application/octet-stream"
end 

if bucket.nil?
  puts "need a bucket"
  exit
end

puts "file: #{local_file}"
puts "bucket: #{bucket}"
puts "mime_type: #{mime_type}"

AWS::S3::Base.establish_connection!(
  :access_key_id     => 'REPLACE_ME',
  :secret_access_key => 'REPLACE_ME'
)

base_name = File.basename(local_file)
 
puts "Uploading #{local_file} as '#{base_name}' to '#{bucket}'"

AWS::S3::S3Object.store(
  base_name,
  File.open(local_file),
  bucket,
  :content_type => mime_type
)
 
puts "Uploaded!"

I can call the script a couple ways:

# with defaults based on extension
$ ruby aws-s3.rb mysong.mp3

# or explicitly (file, bucket, mime-type)
$ ruby aws-s3.rb mysong.mp3 doug_mp3 'audio/mp3'