I've switched my port80 proxy / vanilla server to nginx. it's a
great little server out of russia.

It happens to feature a rather neat thing as well...
when you upgrade the binary , you can have it start up a new binary,
bind to 80 ( along with the existing one ) , then have the old binary
shut down
the effect is a seamless upgrade with no downtime

see: http://wiki.codemongers.com/NginxCommandLine and the section
"Upgrading To a New Binary On The Fly"

is there any way to do that with apache2/mp2 ?

apache doesn't seem to like to bind to any port that something else
is running on. i couldn't find an override anywhere.