A little off topic but you guys seem to know things like this.  Also, I 
would prefer a site that uses FOSS software, just because.

There are sites on the web that allow users to enter a petition and to 
collect "signatures".  Have any of you used these petition sites?  Are any 
of them supposed to be better than others?  I would be concerned mostly 
about sites that harvest email addresses or other information from 
signatories.  Otherwise I just want to know that the site works.

Thanks in advance.

Mike