routing registries question

[hhui () arcfour com (Hui-Hui Hu)]

 naive question: I just noticed that ARIN has a routing registry and was 
 wondering what that does for me. I notice it doesn't mirror RADB very
 well. does it supercede IRR/RADB or is it just another fun tool? 

 (this is not a political question)
 
-h