Evidence Scheduling Plugin
A plugin that will predict how many hours given task or milestone will take. It does its calculation based on previously generated statistics by the same team.
It also gives you predicted shipping dates based on developers' working weeks.
Requires TimingAndEstimationPlugin to work.
If you have any issues, create a new issue here.
Download the zipped source from here.
For every ticket you start make an estimation how long will you have to work until it is finished. When finished, record how long you have actually worked on the it. By doing so you feed statistics into the plugin and for every new ticket it will give you better predictions based on your current estimation.
Good info on what this plugin SHOULD do can be read in Joel's blog: http://www.joelonsoftware.com/items/2007/10/26.html