Via this post i am just sharing my experience [so that it could be useful for the one doing the topic related agile], i don’t mean it is the best tool or so.
Planning poker is a nice way to make estimate in agile medium sized team. Planning poker combined with some group chatting application like Skype makes one of a best way to estimate for an agile team of medium size if they are distributed in different locations.
Following briefly described how a planning poker can be used
Moderator [ for example: project manager/team leader] host the game and invites other. Other team member join the game. Host then writes a task for all to estimate. Each person gives his own independent estimate. If any person gives quite a disagreeing estimate compared to majority then he/she has to give reason why that was his/her estimate [this can be done via skype ]. If the reason is convincing then host restarts the estimating game for that task. When all members gives similar estimate then moderator decides the estimate for that task. In this way all the task are estimated. Then sum of all estimates of task is now used to generate the project or module’s development estimation time.