I was able to create my own system for handling buttons, but it looks kindof crappy. If I ever say that I know anything about building a GUI, I'm lying. I am however, quite good at using established libraries.
I personally think a SDL_GUI library should be up there with SDL_net and SDL_mixer as an essential. It just makes so much sense to me that if all of these different SDL add-ons are established and popular, why isn't there one for handling GUIs? Maybe there is one and I just haven't seen it yet.
On another note, I'm hoping to get a demo out of my game sometime this weekend. I just want to finish another GUI element, the textbox, before showing the demo. This way, I can put the instructions right there in the game.