OK.. 0.0.0.0 aside.. got a serious question...
How do you come up with the IP address of the miner/pool? Looking at raw blocks in block explorer I don't see an IP address anyplace ..

Sigg
The chart uses known IPs of pools (that people report, or that are shown in pool docs for connecting your miner).
That's the right answer to the wrong question.
When a Bitcoin block is found, the node that found it broadcasts it out to other nodes. blockchain.info is connected to hundreds of nodes, so by listening in on the new block announcements, it can quickly determine which Bitcoin node on which IP address found the block.