I mentioned it in one of my reply to following post - http://www.scrum.org/Forums/aft/288
but still thought of giving more details on it.
As per standard scrum process our team was doing the planning poker estimation using the cards given by our Scrum training instructor. We had a couple of issues while doing estimation with cards and team found out an online tool www.planningpoker.com which is really very simple and useful for us for resolving the following problems -
1. People try to cheat and look at their peers card before showing their own. With the online tool you can't see other's card until everyone finishes.
2. Lately we get into a distributed team setup where our team members were located at two different geographic locations. It was very difficult to keep everyone in sync while doing the estimation either using the lotus IM or calling out your story points on phone. The adverse impact of it was that people get influenced by each other and they may change their number based upon what they just heard on the phone.
3. There was not much discussion happening and based upon the majority we were putting the final number for a PBI/Bug. When everyone has the numbers from each individual on their screen then they talk more and ask more questions, leading to better discussions.
4. While your team is on phone there are chances that you may miss out getting input from someone, leading to missing their vote for the estimation. The online tool forces everyone to put their number.
5. While sitting in the same room, we were asking team members to hold up their card high so that rest of the team can see but it was not happening most of the time. With the online tool, put your number and you are done, after getting all votes everyone can see each others number.
Just to make it clear that I am not their sales guy, this worked for us and may be helpful for your team too.