Fedex & UPS implementation

I've been looking for a Ruby implementation of Fedex and UPS.

I've been through their documentation, and think it's really overcomplicated (I'm a bit of a ruby "newbie" myself), so was looking for something simpler. I would only like to use the tracking function.

Has anyone ever worked with something like that and could point me to the right direction on how to implement this?

Try Shopify's active_shipping plugin. It supports UPS, USPS, and FedEx. The developers are planning on adding tracking support (according to the readme), but support is already provided for FedEx tracking:

fdx = FedEx.new(:login => '999999999', :password => '7777777')
tracking_info = fdx.find_tracking_info('tracking number here', :carrier_code => 'fedex_ground') # Ground package

tracking_info.shipment_events.each do |event|
  puts "#{event.name} at #{event.location.city}, #{event.location.state} on #{event.time}. #{event.message}"
end
# => Package information transmitted to FedEx at NASHVILLE LOCAL, TN on Thu Oct 23 00:00:00 UTC 2008. 
# Picked up by FedEx at NASHVILLE LOCAL, TN on Thu Oct 23 17:30:00 UTC 2008. 
# Scanned at FedEx sort facility at NASHVILLE, TN on Thu Oct 23 18:50:00 UTC 2008. 
# Departed FedEx sort facility at NASHVILLE, TN on Thu Oct 23 22:33:00 UTC 2008. 
# Arrived at FedEx sort facility at KNOXVILLE, TN on Fri Oct 24 02:45:00 UTC 2008. 
# Scanned at FedEx sort facility at KNOXVILLE, TN on Fri Oct 24 05:56:00 UTC 2008. 
# Delivered at Knoxville, TN on Fri Oct 24 16:45:00 UTC 2008. Signed for by: T.BAKER

There are a few services that might be worth taking a look at:

http://rocketship.it/

and

http://www.auctioninc.com/info/page/shipping_api

Another one is the shiprush api. http://developer.shiprush.com