looking for guestbook/petition tool without the comments

I am looking for a plugin (or a tool that will be easy to integrate into wordpress) that will give a simple guestbook that will be used for a petition. I don’t want it to be based on wordpress comments, actually I want it out of the wordpress db (in a seperate db or a text file).

Anyone has any recommendation?

Oh, and if it has some sort of anti spam feature it would really be wonderful.

Thanks.