I picked up a Logitech Dual Action controller from eBay. It works great. You can download the 'profiler' from Logitech. I haven't had to use the 'profiler' because Keygrabber does everything I need so far. Makes it handy to use with other programs and games.
I'm using it with all the axis, feedrate increase/decrease, load g-code, cycle start, feedhold, and program rewind. I like it because most of what I do setting things up can be done with it in my left hand. I'll post some pictures later.
They have a ton of them (nearly 100) over there starting at around $11.00 with 'Buy it Now'. Quite a bit cheaper than the shuttle.
Logitech Dual Action controllers on eBay.