I have spent lots of time spotting at IND
in the past (most recently, March 2004).
The best place I have found for outdoor spotting is on the top of the parking garage fronting the terminal; you can get great views of approaches to both parallel runways from the top level of the garage. I haven't been hassled, either. In fact, I met an Indianapolis police officer who shared the same passion as I; he was there spotting at the same time I was (he even had his squad car, his wife and kids).
Inside, I recommend the food court seating area (in the shopping area just before the security checkpoint before concourses B and C). I have sat by the large window while eating; this large window overlooks the apron between concourses C and D. You can see plenty of ATA, CO
, and US action there.
I will praise thee; for I am fearfully and wonderfully made... (Psalm 139:14)