I can drive my PSR3000 using USB off my PC. If I could find a suitable application could I do the same off my Android phone having connected using a USB On The Go cable?

As the 3k is USB 1.1 I suspect not, although the adapter is inexpensive so I might just try it anway!

Could be useful for newer keyboards with USB2 compatability?

All thoughts gratefullly received (although if all you say is "get an iPad" that isn't much help )