[OSList] Software for text message voting?

[Thomas Herrmann]

Anyone who used voting via text message(people using their phones)? Do you know any good software?
In May I will facilitating a large one day OST I shared a bit about earlier. My sponsor counts on 1000 participants. 
The voting will be on the topics that came up on the agenda as we cannot give time to read all reports… 

Using such a software, the results will be visible directly. In the evening the topics will be clustered by a smaller group. This may change the visible results. 

The results will be used the next day when politicians on the national level will have them as input to what is important regarding creating a viable/lusty country side in Sweden.

Any other ideas about voting with such a large group?
Cheers
Thomas