First of all: I LOVE RDM, use it daily, bought it and recommend it to anyone that asks me for a product like this. :-)
Second: I use many features and one of them is the Password Generator.
I'd love having also a TCP/IP Random Port Generator. I'll try to explain why and when it comes useful. Many times I must select a non-default port for several kind of services: HTTP, RDP, and so on. This is necessary for 2 reasons: security (using non-default ports is better) and concurrency (the default port might be already used). The issue is that some ports are already known/reserved so I must chose a non-reserved port (Wikipedia helps) but it should at least not be ALWAYS the same (8080 is a non-default port well known as much as 80). That's it.
It's a good idea and it's not really hard to add. RDM could also verify in his list to check if the port is already used by another session.