The Kids Grid is a club of kids who were based in The Under and in Pyrite Town. Secc of Pyrite established an internet connection with Nett in The Under. During the events of Pokémon Colosseum, they were a primary source of information to Wes. Being kids, they were disregarded as threats by Cipher and were thus able to gather information effectively. They were integral to the downfall of the original Shadow Pokémon plot, providing Wes with locations of Trainers, a list of Shadow Pokémon, and valuable contacts.
Secc was the founder of the group, but much of the work was done by Nett, who successfully hacked Cipher's computer system and decoded the Data Rom containing the list of Shadow Pokémon. The other members of the group had their own parts as well, from running errands, to gathering information, to eavesdropping.
The back room of Duking's house in Pyrite Town functioned as a rough headquarters for the Pyrite branch of the group, while the members in The Under worked out of the basement of Nett's house.
Prior to the events of Pokémon XD: Gale of Darkness, former members of the Kids Grid went and formed the ONBS, a broadcasting station based in Pyrite Town. In this game again, Nett helps with decoding data.