I recommend setting up a virtual hosting environment, so that you can assign unique project names to the servers and address them accordingly, e.g.
http://myproject1/,
http://myproject2 etc. and don't have to fiddle with port numbers.
This gets especially useful when you have a webinterface to manage these server instances, so you can start and stop them from the browser and have one page that links to them all. I know one guy who has written a simple webinterface for daemontools for internal use at my previous company - if you're interested I'll ask him to upload it somewhere.
It would also be nice if these instances could selectively be made available online, so that you could e.g. open http://myproject1.mydomain.com/ for the public or only for the IP address of a client, but that involves some control over DNS and was not implemented at that setup unfortunately.
