yes, there is, but it's kind of primitive. You will have to set up your own web server, build a custom XML application for your IP phones with URLS to the Ready, Not Ready, etc states. There's a drawback, though, this static application will have no idea about the actual state of the agent so for instance, it will present the agent with the option to go Ready even though the agent is Ready etc.
Is it something you can work with?
Can you also give us the UCCX version?