Who uses RADB/IRR?

I'd like to find out which networks use the RADB or IRR databases to
build their routing policies, and how to look at their current databases
or access looking glass or equivalent systems.

It's becoming difficult to take a network multihomed without having
parts of the net appear to be black holed in other parts of the world.
It appears difficult to ascertain which networks are doing what with

So far I am aware of CW.NET and ANS.NET using the routing databases to
build their policies, but am not aware of a way to look at their tables.
If anyone has pointers to their resources, or those of other nets using
the routing registries, please let me know.