[GTALUG] Making RPM from directory tree?

To RPM guys, I have a directory tree, created from "make install DESTDIR=...". Now, I want to make RPM package from the tree. Online docs are too verbose and confusing. 1. Is there GUI app with appropriate fill in boxes? 2. Is there command line utility? In Slackware, it's just "makepkg". Background: I use "netpipes-4.2" a lot. Debian and Slackware have it, but Redhat variants don't. I can use netcat and pipe (and I do), but there are so many variations (ie. nc, netcat, ncat), each with different behaviour and options. I like to use what I'm familiar with. So, I downloaded the source, compiled it, and installed to a directory. Now what?