We are using JMX to monitor our web servers. If you have ever tried to employ JMX you must already know what a pain in the neck it is. So I just skip that part. I tried jmanage, and it was cool, but required a password to be entered at start time, and required an additional java process to run on a web server, and it was pretty slow.
So I came up with an idea of creating a web servlet that would interface with JMX mbeans. The source can be found here: http://code.google.com/p/jmxwebadapter/ along with instructions. It requires Spring Framework to run.
You can use this both as a user interface and as a REST API to your MBeans.