Before my time, our company used to use Keystone integrated with our own web-based accounts system to do support, order tracking and so on.
After playing with RT myself for a while, I implemented it for our support desk about 9 months ago. 10000 tickets later, it's been a success - we've slowly been making tweaks here and there to both RT and the way we use it.
I'm a pretty experienced (~10 years) perl programmer, but I have to admit I've found RT a bit frustrating to work with. It's obvious that a lot of thought has gone into the architecture of the application, and how it fits together, but I've found very little documentation to allow even the experienced user to customise and extend it. I was very pleased to find this Wiki this afternoon!
At the moment, I'm sure I'll ask more questions than answer them, but I hope that will change...
My current RT-related interests are:
- spam filtering, but somehow not making our abuse@.... address useless
- using RT for a 'todo' list with rt-escalate and queue-specific priorities to provide a dynamic list of outstanding tasks
- integration with our network monitor and accounting/ordering system
- integration into a larger customer intranet/portal with other service information (statistics, ordering etc)