Metadata comparison
Check out Tquila's org. diff. http://www.tquila.com/blog/2015/01/08/org-compare
Edit: the SF Toolkit is now hosted at: http://sftoolkit.co/
I was trying out : https://gearset.com/ a nice comparison tool that let you deploy changes as well...
I use copado deployer
https://appexchange.salesforce.com/listingDetail?listingId=a0N3000000B3dgGEAR
Does org diff, git integration and fast deployments.
Cheers