Just thought I'd update. Got an OTG cable and it works with KitKat. It works with a mouse and external flash drive, but there is no native support. You have to install the app StickMount (which requires root), then it will work. It mounts USB drive to /sdcard/usbStorage/sda1. As far as I can tell, FAT and FAT32 are read/write, exFAT and NTFS are read-only.
It's pretty nice for backup and restore using Titanium without using internal storage space.