Binary downloads

[Blair Zajac]

I blew away my /opt/local to start over after I got a SQL error I asked 
about in a previous thread [1] and noticed that the new build is using 
binary downloads.

1) Were binary downloads enabled for a while and it's just because I'm 
reintalling "core" packages that I'm seeing this?

2) Is there a way to disable binary downloads and always compile myself?

3) What file format is the rmd160 files?  Are those signatures or checksums?

Thanks,
Blair

[1] 
http://lists.macosforge.org/pipermail/macports-dev/2012-April/018514.html