If you want a full, completely customized graphical UI, then control pages are definitely the simplest way. You could build your own custom website that uses the
RESTful API to control Indigo. But getting images to not drag would be an exercise for you to figure out (I think it can be done with CSS images but I've not really looked into it).
Depending on what your target platform is, you could try one of the other clients that have Indigo baked in:
DomoPad (for Android),
Home Remote or
Simple Control. There are also other UI construction kits that allow the use of HTTP commands (like
iRule for instance) - as long as they support HTTP Digest Authentication then they can be configured to talk to
Indigo's RESTful API.
Finally, if you're a developer, you can develop your own client (a la DomoPad) that has all the same features of our Indigo Touch clients. The APIs for that are available - contact us for more information.