http://sci.tech-archive.net/Archive/.../msg00020.html
so thats neat a Volcanic mountain there^
http://www.youtube.com/watch?v=M08WLC-jyZ4
this is kinda cool too^
http://www.youtube.com/watch?v=F6-_UTU_bJ0
And this one is very interesting^
Now some things maybe obvious but maybe not. Think how great if you could man-make these. Or how dangerous accidently puncturing one could be.