PlanITpoker is a fun, easy to use tool for project teams to estimate tasks.
Players vote on each task using cards without seeing what other players are voting. After all have voted the results are revealed and the estimates discussed until a consensus is reached. This technique of estimating is sometimes called planning poker or Scrum poker.
PlanITPoker is totally free to use and ideal for distributed software teams using Agile development methodologies.
"Nearly every great advance in science arises from a crisis in the old theory, through an endeavor to find a way out of the difficulties created. We must examine old ideas, old theories, although they belong to the past, for this is the only way to understand the importance of the new ones and the extent of their validity."